{"segment":[{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[4]],"list":[{"point":5,"ques":"Cho \u0111i\u1ec3m M thu\u1ed9c \u0111\u01b0\u1eddng th\u1eb3ng d. Kh\u1eb3ng \u0111\u1ecbnh n\u00e0o sau \u0111\u00e2y \u0111\u00fang? ","select":["A. \u0110i\u1ec3m M n\u1eb1m tr\u00ean \u0111\u01b0\u1eddng th\u1eb3ng d","B. \u0110\u01b0\u1eddng th\u1eb3ng d \u0111i qua \u0111i\u1ec3m M","C. \u0110\u01b0\u1eddng th\u1eb3ng d ch\u1ee9a \u0111i\u1ec3m M","D. C\u1ea3 A, B, C \u0111\u1ec1u \u0111\u00fang"],"hint":"","explain":" <span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span> <br\/> <center><img src='https://www.luyenthi123.com/file/luyenthi123/lop6/toan/hinhhoc/bai7/lv1/img\/H617_D101.png' \/><\/center> <br\/> V\u00ec \u0111i\u1ec3m M thu\u1ed9c \u0111\u01b0\u1eddng th\u1eb3ng d n\u00ean: <br\/> \u0110i\u1ec3m M thu\u1ed9c \u0111\u01b0\u1eddng th\u1eb3ng d hay M n\u1eb1m tr\u00ean \u0111\u01b0\u1eddng th\u1eb3ng d <br\/> \u0110\u01b0\u1eddng th\u1eb3ng d \u0111i qua \u0111i\u1ec3m M <br\/> \u0110\u01b0\u1eddng th\u1eb3ng d ch\u1ee9a \u0111i\u1ec3m M <br\/> V\u1eady <span class='basic_pink'> c\u1ea3 3 \u0111\u00e1p \u00e1n tr\u00ean \u0111\u1ec1u \u0111\u00fang <\/span> ","column":2}]}],"id_ques":2041},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[4]],"list":[{"point":5,"ques":"Cho h\u00ecnh v\u1ebd: <br\/> <center><img src='https://www.luyenthi123.com/file/luyenthi123/lop6/toan/hinhhoc/bai7/lv1/img\/H617_D102.png' \/><\/center> <br\/> Ph\u00e1t bi\u1ec3u n\u00e0o sau \u0111\u00e2y sai?","select":["A. Ba \u0111i\u1ec3m A, B, C th\u1eb3ng h\u00e0ng","B. \u0110i\u1ec3m B n\u1eb1m gi\u1eefa hai \u0111i\u1ec3m A v\u00e0 C","C. Hai \u0111i\u1ec3m A, B n\u1eb1m c\u00f9ng ph\u00eda \u0111\u1ed1i v\u1edbi \u0111i\u1ec3m C","D. Ba ph\u00e1t bi\u1ec3u tr\u00ean \u0111\u1ec1u sai"],"hint":"","explain":" <span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span> <br\/> Quan s\u00e1t h\u00ecnh v\u1ebd ta c\u00f3: <br\/> Ba \u0111i\u1ec3m A, B, C th\u1eb3ng h\u00e0ng <br\/> \u0110i\u1ec3m B n\u1eb1m gi\u1eefa hai \u0111i\u1ec3m A v\u00e0 C <br\/> Hai \u0111i\u1ec3m A, B n\u1eb1m c\u00f9ng ph\u00eda \u0111\u1ed1i v\u1edbi \u0111i\u1ec3m C <br\/> <span class='basic_pink'>V\u1eady kh\u1eb3ng \u0111\u1ecbnh sai l\u00e0: D<\/span> ","column":2}]}],"id_ques":2042},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[1]],"list":[{"point":5,"ques":"Cho h\u00ecnh v\u1ebd: <br\/> <center><img src='https://www.luyenthi123.com/file/luyenthi123/lop6/toan/hinhhoc/bai7/lv1/img\/H617_D103.png' \/><\/center> <br\/> Ph\u00e1t bi\u1ec3u n\u00e0o sau \u0111\u00e2y \u0111\u00fang?","select":["A. \u0110\u01b0\u1eddng th\u1eb3ng ab c\u1eaft \u0111\u01b0\u1eddng th\u1eb3ng xy t\u1ea1i M","B. \u0110i\u1ec3m M thu\u1ed9c \u0111\u01b0\u1eddng th\u1eb3ng ab nh\u01b0ng kh\u00f4ng thu\u1ed9c \u0111\u01b0\u1eddng th\u1eb3ng xy","C. \u0110i\u1ec3m M thu\u1ed9c \u0111\u01b0\u1eddng th\u1eb3ng xy nh\u01b0ng kh\u00f4ng thu\u1ed9c \u0111\u01b0\u1eddng th\u1eb3ng ab","D. Hai \u0111\u01b0\u1eddng th\u1eb3ng ab v\u00e0 \u0111\u01b0\u1eddng th\u1eb3ng xy kh\u00f4ng c\u00f3 \u0111i\u1ec3m n\u00e0o chung "],"hint":"","explain":" <span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span> <br\/> Quan s\u00e1t h\u00ecnh v\u1ebd ta c\u00f3: <br\/> \u0110\u01b0\u1eddng th\u1eb3ng ab c\u1eaft \u0111\u01b0\u1eddng th\u1eb3ng xy t\u1ea1i M <br\/> Do \u0111\u00f3 M thu\u1ed9c \u0111\u01b0\u1eddng th\u1eb3ng ab v\u00e0 M thu\u1ed9c \u0111\u01b0\u1eddng th\u1eb3ng xy <br\/> <span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0: A<\/span> ","column":1}]}],"id_ques":2043},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[2]],"list":[{"point":5,"ques":"Cho h\u00ecnh v\u1ebd: <br\/> <center><img src='https://www.luyenthi123.com/file/luyenthi123/lop6/toan/hinhhoc/bai7/lv1/img\/H617_D109.png' \/><\/center> <br\/> Kh\u1eb3ng \u0111\u1ecbnh n\u00e0o sau \u0111\u00e2y \u0111\u00fang?","select":["A. $P \\in a; P \\in c$","B. $Q \\in c; Q \\in b$","C. $R \\in a; R \\notin c$","D. $P \\notin b; P \\in a$"],"hint":"","explain":" <span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span> <br\/> Quan s\u00e1t h\u00ecnh v\u1ebd ta c\u00f3: <br\/> +) \u0110i\u1ec3m P n\u1eb1m tr\u00ean \u0111\u01b0\u1eddng th\u1eb3ng d nh\u01b0ng \u0111i\u1ec3m P kh\u00f4ng n\u1eb1m tr\u00ean \u0111\u01b0\u1eddng th\u1eb3ng c <br\/> $\\Rightarrow$ Kh\u1eb3ng \u0111\u1ecbnh \"P $\\in$ a; P $\\in$ c\" l\u00e0 <b> SAI <\/b> <br\/> +) \u0110i\u1ec3m Q n\u1eb1m tr\u00ean \u0111\u01b0\u1eddng th\u1eb3ng c v\u00e0 \u0111i\u1ec3m Q n\u1eb1m tr\u00ean \u0111\u01b0\u1eddng th\u1eb3ng b <br\/> $\\Rightarrow$ Kh\u1eb3ng \u0111\u1ecbnh \"Q $\\in$ c; Q $\\in$ b\" l\u00e0 <b> \u0110\u00daNG <\/b> <br\/> +) \u0110i\u1ec3m R n\u1eb1m tr\u00ean \u0111\u01b0\u1eddng th\u1eb3ng c v\u00e0 R n\u1eb1m tr\u00ean \u0111\u01b0\u1eddng th\u1eb3ng a <br\/> $\\Rightarrow$ Kh\u1eb3ng \u0111\u1ecbnh \"R $\\in$ a; R $\\notin$ c\" l\u00e0 <b> SAI <\/b> <br\/> +) \u0110i\u1ec3m P n\u1eb1m tr\u00ean \u0111\u01b0\u1eddng th\u1eb3ng a v\u00e0 \u0111\u01b0\u1eddng th\u1eb3ng b <br\/> $\\Rightarrow$ Kh\u1eb3ng \u0111\u1ecbnh \"P $\\notin$ b; P $\\in$ a \" l\u00e0 <b> SAI <\/b> <br\/> <span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0: B<\/span> ","column":2}]}],"id_ques":2044},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[4]],"list":[{"point":5,"ques":"Cho 3 \u0111i\u1ec3m A, B, C nh\u01b0 h\u00ecnh v\u1ebd: <br\/> <center><img src='https://www.luyenthi123.com/file/luyenthi123/lop6/toan/hinhhoc/bai7/lv1/img\/H617_D112.png' \/><\/center> <br\/> Kh\u1eb3ng \u0111\u1ecbnh n\u00e0o sau \u0111\u00e2y \u0111\u00fang? ","select":["A. \u0110i\u1ec3m A n\u1eb1m gi\u1eefa hai \u0111i\u1ec3m B v\u00e0 C","B. \u0110i\u1ec3m B n\u1eb1m gi\u1eefa hai \u0111i\u1ec3m A v\u00e0 C","C. \u0110i\u1ec3m C n\u1eb1m gi\u1eefa hai \u0111i\u1ec3m A v\u00e0 B","D. Kh\u00f4ng c\u00f3 \u0111i\u1ec3m n\u00e0o n\u1eb1m gi\u1eefa hai \u0111i\u1ec3m c\u00f2n l\u1ea1i"],"hint":"","explain":" <span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span> <br\/> V\u00ec 3 \u0111i\u1ec3m A, B, C nh\u01b0 h\u00ecnh v\u1ebd l\u00e0 3 \u0111i\u1ec3m kh\u00f4ng th\u1eb3ng h\u00e0ng <br\/> N\u00ean kh\u00f4ng c\u00f3 \u0111i\u1ec3m n\u00e0o n\u1eb1m gi\u1eefa hai \u0111i\u1ec3m c\u00f2n l\u1ea1i <br\/> <span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0: D <\/span> ","column":2}]}],"id_ques":2045},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[3]],"list":[{"point":5,"ques":"C\u00f3 th\u1ec3 v\u1ebd \u0111\u01b0\u1ee3c bao nhi\u00eau \u0111\u01b0\u1eddng th\u1eb3ng \u0111i qua hai trong s\u1ed1 8 \u0111i\u1ec3m ph\u00e2n bi\u1ec7t, trong \u0111\u00f3 kh\u00f4ng c\u00f3 3 \u0111i\u1ec3m n\u00e0o th\u1eb3ng h\u00e0ng. ","select":["A. 8","B. 16","C. 28","D. S\u1ed1 kh\u00e1c"],"hint":"","explain":" <span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span> <br\/> V\u00ec qua hai \u0111i\u1ec3m lu\u00f4n v\u1ebd \u0111\u01b0\u1ee3c m\u1ed9t \u0111\u01b0\u1eddng th\u1eb3ng <br\/> N\u00ean qua 10 \u0111i\u1ec3m ph\u00e2n bi\u1ec7t trong \u0111\u00f3 kh\u00f4ng c\u00f3 3 \u0111i\u1ec3m n\u00e0o th\u1eb3ng h\u00e0ng v\u1ebd \u0111\u01b0\u1ee3c: <br\/> $\\dfrac{8 . (8 - 1)}{2} = 28$ (\u0111\u01b0\u1eddng th\u1eb3ng) <br\/> <span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0: C <\/span> ","column":2}]}],"id_ques":2046},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[3]],"list":[{"point":5,"ques":"Cho h\u00ecnh v\u1ebd: <br\/> <center><img src='https://www.luyenthi123.com/file/luyenthi123/lop6/toan/hinhhoc/bai7/lv1/img\/H617_D113.png' \/><\/center> <br\/> Kh\u1eb3ng \u0111\u1ecbnh n\u00e0o sau \u0111\u00e2y \u0111\u00fang? ","select":["A. IA v\u00e0 IB l\u00e0 hai tia \u0111\u1ed1i nhau","B. AB v\u00e0 DA l\u00e0 hai tia chung g\u1ed1c","C. IB v\u00e0 ID l\u00e0 hai tia \u0111\u1ed1i nhau","D. AI v\u00e0 AC l\u00e0 hai tia ph\u00e2n bi\u1ec7t"],"hint":"","explain":" <span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span> <br\/> Quan s\u00e1t h\u00ecnh v\u1ebd ta c\u00f3: <br\/> +) IA v\u00e0 IB l\u00e0 hai tia chung g\u1ed1c I, IA v\u00e0 IB kh\u00f4ng c\u00f9ng thu\u1ed9c m\u1ed9t \u0111\u01b0\u1eddng th\u1eb3ng <br\/> $\\Rightarrow$ Tia IA v\u00e0 tia IB kh\u00f4ng \u0111\u1ed1i nhau <br\/> +) Tia AB c\u00f3 g\u1ed1c l\u00e0 A, tia DA c\u00f3 g\u1ed1c l\u00e0 D <br\/> $\\Rightarrow$ AB v\u00e0 DA l\u00e0 hai tia kh\u00f4ng chung g\u1ed1c <br\/> IB v\u00e0 ID c\u00f3 chung g\u1ed1c D; tia IB v\u00e0 tia ID t\u1ea1o th\u00e0nh m\u1ed9t \u0111\u01b0\u1eddng th\u1eb3ng <br\/> $\\Rightarrow$ IB v\u00e0 ID l\u00e0 hai tia \u0111\u1ed1i nhau <br\/> +) AI v\u00e0 AC c\u00f3 chung g\u1ed1c A; tia AI v\u00e0 tia AC c\u00f9ng thu\u1ed9c m\u1ed9t n\u1eeda \u0111\u01b0\u1eddng th\u1eb3ng <br\/> $\\Rightarrow$ AI v\u00e0 AC l\u00e0 hai tia tr\u00f9ng nhau <br\/> <span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0: C <\/span> ","column":2}]}],"id_ques":2047},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[2]],"list":[{"point":5,"ques":"Cho \u0111i\u1ec3m I thu\u1ed9c \u0111o\u1ea1n th\u1eb3ng AB. Bi\u1ebft AI = 4cm, AB = 7cm. T\u00ednh \u0111\u1ed9 d\u00e0i BI.","select":["A. BI = 11cm","B. BI = 3cm","C. BI = 5cm","D. M\u1ed9t s\u1ed1 kh\u00e1c"],"hint":"","explain":" <span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/> <b> B\u01b0\u1edbc 1: <\/b> Ch\u1ec9 ra \u0111i\u1ec3m I n\u1eb1m gi\u1eefa hai \u0111i\u1ec3m A v\u00e0 B <br\/> <b> B\u01b0\u1edbc 2: <\/b> D\u1ef1a v\u00e0o t\u00ednh ch\u1ea5t c\u1ed9ng \u0111\u1ed9 d\u00e0i \u0111o\u1ea1n th\u1eb3ng \u0111\u1ec3 t\u00ednh IB <\/span> <br\/><br\/> <span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span> <br\/><span class='basic_left'><b> T\u00f3m t\u1eaft: <\/b> <br\/> Tr\u00ean \u0111o\u1ea1n th\u1eb3ng AB <br\/> AI = 4cm <br\/> AB = 7cm <br\/> T\u00ednh IB = ? <\/span> <br\/> <center><img src='https://www.luyenthi123.com/file/luyenthi123/lop6/toan/hinhhoc/bai7/lv1/img\/H617_D115.png' \/><\/center> <br\/> V\u00ec \u0111i\u1ec3m I th\u1eb3ng AB; AI = 4cm, AB = 7cm m\u00e0 4cm < 7cm n\u00ean AI < AB <br\/> $\\Rightarrow$ \u0110i\u1ec3m I n\u1eb1m gi\u1eefa hai \u0111i\u1ec3m A v\u00e0 B <br\/> $\\begin{align*} \\Rightarrow AI + IB &= AB \\\\ 4cm + IB &= 7cm \\\\ IB &= 7cm - 4cm \\\\ IB &= 3cm \\end{align*}$<br\/> <span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0: B <\/span> ","column":2}]}],"id_ques":2048},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[3]],"list":[{"point":5,"ques":"Tr\u00ean tia Oa l\u1ea5y hai \u0111i\u1ec3m M, N sao cho OM = 3cm, ON = 6cm. T\u00ednh MN.","select":["A. MN = 9cm","B. MN = 8cm","C. MN = 3cm","D. M\u1ed9t s\u1ed1 kh\u00e1c"],"hint":"","explain":" <span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/> <b> B\u01b0\u1edbc 1: <\/b> Ch\u1ec9 ra \u0111i\u1ec3m M n\u1eb1m gi\u1eefa hai \u0111i\u1ec3m O v\u00e0 N <br\/> <b> B\u01b0\u1edbc 2: <\/b> D\u1ef1a v\u00e0o t\u00ednh ch\u1ea5t c\u1ed9ng \u0111\u1ed9 d\u00e0i \u0111o\u1ea1n th\u1eb3ng \u0111\u1ec3 t\u00ednh MN <\/span> <br\/><br\/> <span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span> <br\/> <span class='basic_left'><b> T\u00f3m t\u1eaft: <\/b> <br\/> Tr\u00ean tia Oa <br\/> OM = 3cm <br\/> ON = 6cm <br\/> T\u00ednh MN = ? <\/span><br\/> <center><img src='https://www.luyenthi123.com/file/luyenthi123/lop6/toan/hinhhoc/bai7/lv1/img\/H617_D116.png' \/><\/center> <br\/> Tr\u00ean tia Oa c\u00f3: OM = 3cm, ON = 6cm <br\/> M\u00e0 3cm < 6cm n\u00ean OM < ON <br\/> <br\/> $\\Rightarrow$ \u0110i\u1ec3m M n\u1eb1m gi\u1eefa hai \u0111i\u1ec3m O v\u00e0 N <br\/> $\\begin{align*} \\Rightarrow OM + MN &= ON \\\\ 3cm + MN &= 6cm \\\\ MN &= 6cm - 3cm \\\\ MN &= 3cm \\end{align*}$<br\/> <span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0: C <\/span> ","column":2}]}],"id_ques":2049},{"time":9,"part":[{"title":"\u0110i\u1ec1n s\u1ed1 th\u00edch h\u1ee3p v\u00e0o ch\u1ed7 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank","correct":[[["45"]]],"list":[{"point":5,"width":60,"type_input":"","ques":"Cho tr\u01b0\u1edbc 10 \u0111i\u1ec3m, v\u1ebd c\u00e1c \u0111\u01b0\u1eddng th\u1eb3ng \u0111i qua c\u00e1c c\u1eb7p \u0111i\u1ec3m. Trong c\u00e1c \u0111i\u1ec3m tr\u00ean kh\u00f4ng c\u00f3 3 \u0111i\u1ec3m n\u00e0o th\u1eb3ng h\u00e0ng. H\u1ecfi v\u1ebd \u0111\u01b0\u1ee3c bao nhi\u00eau \u0111\u01b0\u1eddng th\u1eb3ng?<br\/> \u0110\u00e1p \u00e1n l\u00e0: _input_ \u0111\u01b0\u1eddng th\u1eb3ng ","hint":"","explain":"<span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/> T\u00ednh s\u1ed1 \u0111\u01b0\u1eddng th\u1eb3ng theo c\u00f4ng th\u1ee9c: $\\dfrac{n . (n - 1)}{2}$ <\/span> <br\/><br\/><span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span> <br\/> V\u00ec qua hai \u0111i\u1ec3m lu\u00f4n v\u1ebd \u0111\u01b0\u1ee3c m\u1ed9t \u0111\u01b0\u1eddng th\u1eb3ng <br\/> N\u00ean qua 10 \u0111i\u1ec3m v\u1ebd \u0111\u01b0\u1ee3c s\u1ed1 \u0111\u01b0\u1eddng th\u1eb3ng l\u00e0: <br\/> $\\dfrac{10 . (10 - 1)}{2} = 45$ (\u0111\u01b0\u1eddng th\u1eb3ng) <br\/> V\u1eady s\u1ed1 c\u1ea7n \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u00e0: <span class='basic_pink'> 45 <\/span> "}]}],"id_ques":2050},{"time":9,"part":[{"title":"\u0110i\u1ec1n s\u1ed1 th\u00edch h\u1ee3p v\u00e0o ch\u1ed7 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank","correct":[[["8"]]],"list":[{"point":5,"width":60,"type_input":"","ques":"Cho tr\u01b0\u1edbc 5 \u0111i\u1ec3m trong \u0111\u00f3 c\u00f3 3 \u0111i\u1ec3m th\u1eb3ng h\u00e0ng. V\u1ebd c\u00e1c \u0111\u01b0\u1eddng th\u1eb3ng \u0111i qua c\u00e1c c\u1eb7p \u0111i\u1ec3m. H\u1ecfi v\u1ebd \u0111\u01b0\u1ee3c bao nhi\u00eau \u0111\u01b0\u1eddng th\u1eb3ng?<br\/> \u0110\u00e1p \u00e1n l\u00e0: _input_ \u0111\u01b0\u1eddng th\u1eb3ng ","hint":"","explain":"<span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/> <b> B\u01b0\u1edbc 1: <\/b> T\u00ednh s\u1ed1 \u0111\u01b0\u1eddng th\u1eb3ng theo c\u00f4ng th\u1ee9c: $\\dfrac{n . (n - 1)}{2}$ (1) <br\/><b> B\u01b0\u1edbc 2: <\/b> T\u00ednh s\u1ed1 \u0111\u01b0\u1eddng th\u1eb3ng v\u1ebd \u0111\u01b0\u1ee3c qua 3 \u0111i\u1ec3m (2)<br\/> <b> B\u01b0\u1edbc 3: <\/b> V\u00ec qua 3 \u0111i\u1ec3m th\u1eb3ng h\u00e0ng ch\u1ec9 v\u1ebd \u0111\u01b0\u1ee3c 1 \u0111\u01b0\u1eddng th\u1eb3ng <br\/> N\u00ean s\u1ed1 \u0111\u01b0\u1eddng th\u1eb3ng v\u1ebd \u0111\u01b0\u1ee3c l\u00e0: <br\/> (1) - (2) + 1 <\/span> <br\/><br\/><span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span> <br\/> V\u00ec qua hai \u0111i\u1ec3m lu\u00f4n v\u1ebd \u0111\u01b0\u1ee3c m\u1ed9t \u0111\u01b0\u1eddng th\u1eb3ng <br\/> N\u00ean qua 5 \u0111i\u1ec3m kh\u00f4ng th\u1eb3ng h\u00e0ng v\u1ebd \u0111\u01b0\u1ee3c s\u1ed1 \u0111\u01b0\u1eddng th\u1eb3ng l\u00e0: <br\/> $\\dfrac{5 . (5 - 1)}{2} = 10$ (\u0111\u01b0\u1eddng th\u1eb3ng) <br\/> Qua 3 \u0111i\u1ec3m kh\u00f4ng th\u1eb3ng h\u00e0ng v\u1ebd \u0111\u01b0\u1ee3c s\u1ed1 \u0111\u01b0\u1eddng th\u1eb3ng l\u00e0: <br\/> $\\dfrac{3 . (3 - 1)}{2} = 3$ (\u0111\u01b0\u1eddng th\u1eb3ng) <br\/> V\u00ec qua 3 \u0111i\u1ec3m th\u1eb3ng h\u00e0ng ch\u1ec9 v\u1ebd \u0111\u01b0\u1ee3c m\u1ed9t \u0111\u01b0\u1eddng th\u1eb3ng <br\/> N\u00ean qua 5 \u0111i\u1ec3m trong \u0111\u00f3 c\u00f3 3 \u0111i\u1ec3m th\u1eb3ng h\u00e0ng v\u1ebd \u0111\u01b0\u1ee3c s\u1ed1 \u0111\u01b0\u1eddng th\u1eb3ng l\u00e0: <br\/> 10 - 3 + 1 = 8 (\u0111\u01b0\u1eddng th\u1eb3ng) <br\/> V\u1eady s\u1ed1 c\u1ea7n \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u00e0: <span class='basic_pink'> 8 <\/span> <br\/> <span class='basic_green'><i> L\u01b0u \u00fd: <\/b> Khi l\u00e0m b\u00e0i t\u1eadp d\u1ea1ng n\u00e0y khi t\u00ednh s\u1ed1 \u0111\u01b0\u1eddng th\u1eb3ng v\u1ebd \u0111\u01b0\u1ee3c ta c\u1ea7n tr\u1eeb s\u1ed1 \u0111\u01b0\u1eddng th\u1eb3ng \u0111\u00e3 gi\u1ea3m \u0111i do qua a \u0111i\u1ec3m th\u1eb3ng h\u00e0ng ch\u1ec9 v\u1ebd \u0111\u01b0\u1ee3c m\u1ed9t \u0111\u01b0\u1eddng th\u1eb3ng<\/span> "}]}],"id_ques":2051},{"time":9,"part":[{"title":"\u0110i\u1ec1n s\u1ed1 th\u00edch h\u1ee3p v\u00e0o ch\u1ed7 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank","correct":[[["10"]]],"list":[{"point":5,"width":60,"type_input":"","ques":"Cho tr\u01b0\u1edbc 5 \u0111i\u1ec3m trong \u0111\u00f3 c\u00f3 4 \u0111i\u1ec3m th\u1eb3ng h\u00e0ng. V\u1ebd c\u00e1c \u0111o\u1ea1n th\u1eb3ng \u0111i qua c\u00e1c c\u1eb7p \u0111i\u1ec3m. H\u1ecfi v\u1ebd \u0111\u01b0\u1ee3c bao nhi\u00eau \u0111o\u1ea1n th\u1eb3ng?<br\/> \u0110\u00e1p \u00e1n l\u00e0: _input_ \u0111o\u1ea1n th\u1eb3ng ","hint":"","explain":"<span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/> T\u00ednh s\u1ed1 \u0111o\u1ea1n th\u1eb3ng theo c\u00f4ng th\u1ee9c: $\\dfrac{n . (n - 1)}{2}$ \u0111o\u1ea1n th\u1eb3ng <\/span> <br\/><br\/><span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span> <br\/> V\u00ec qua 2 \u0111i\u1ec3m lu\u00f4n v\u1ebd \u0111\u01b0\u1ee3c m\u1ed9t \u0111o\u1ea1n th\u1eb3ng <br\/> N\u00ean qua 5 \u0111i\u1ec3m v\u1ebd \u0111\u01b0\u1ee3c s\u1ed1 \u0111o\u1ea1n th\u1eb3ng l\u00e0: <br\/> $\\dfrac{5 . (5 - 1)}{2} = 10$ (\u0111o\u1ea1n th\u1eb3ng) <br\/> V\u1eady s\u1ed1 c\u1ea7n \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u00e0: <span class='basic_pink'> 10 <\/span> <br\/> <span class='basic_green'> <i> L\u01b0u \u00fd: <\/span> Qua 2 \u0111i\u1ec3m ph\u00e2n bi\u1ec7t lu\u00f4n v\u1ebd \u0111\u01b0\u1ee3c m\u1ed9t \u0111o\u1ea1n th\u1eb3ng <br\/> N\u00ean qua n \u0111i\u1ec3m th\u1eb3ng h\u00e0ng lu\u00f4n v\u1ebd \u0111\u01b0\u1ee3c $\\dfrac{n . (n - 1)}{2}$ \u0111o\u1ea1n th\u1eb3ng <br\/> V\u1edbi d\u1ea1ng b\u00e0i n\u00e0y h\u1ecdc sinh hay m\u1eafc sai l\u1ea7m l\u00e0 qua c\u00e1c \u0111i\u1ec3m th\u1eb3ng h\u00e0ng ch\u1ec9 v\u1ebd \u0111\u01b0\u1ee3c m\u1ed9t \u0111o\u1ea1n th\u1eb3ng <br\/> Do v\u1eady c\u00f4ng th\u1ee9c tr\u00ean v\u1eabn \u0111\u00fang cho tr\u01b0\u1eddng h\u1ee3p trong n \u0111i\u1ec3m \u0111\u00f3 c\u00f3 a \u0111i\u1ec3m th\u1eb3ng h\u00e0ng <\/i><\/span> "}]}],"id_ques":2052},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[3]],"list":[{"point":5,"ques":"Cho \u0111i\u1ec3m M v\u00e0 \u0111i\u1ec3m N n\u1eb1m tr\u00ean \u0111\u01b0\u1eddng th\u1eb3ng a nh\u01b0ng kh\u00f4ng n\u1eb1m tr\u00ean \u0111\u01b0\u1eddng th\u1eb3ng b. C\u00e1ch ghi n\u00e0o sau \u0111\u00e2y \u0111\u00fang?","select":["A. $M \\in a, N \\notin a; M \\in b; N \\in b$","B. $M \\notin a; N \\in a; M \\in b; N \\in b$","C. $M \\in a; N \\in a; M \\notin b; N \\notin b$","D. $M \\notin a; M \\in b; N \\in a; N \\notin b$"],"hint":"","explain":" <span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span> Theo \u0111\u1ec1 b\u00e0i ta c\u00f3 h\u00ecnh v\u1ebd: <br\/> <center><img src='https://www.luyenthi123.com/file/luyenthi123/lop6/toan/hinhhoc/bai7/lv1/img\/H617_D120.png' \/><\/center><br\/> V\u00ec \u0111i\u1ec3m M v\u00e0 \u0111i\u1ec3m N n\u1eb1m tr\u00ean \u0111\u01b0\u1eddng th\u1eb3ng a <br\/> N\u00ean M $\\in a$ v\u00e0 N $\\in a$ <br\/> \u0110i\u1ec3m M, N kh\u00f4ng n\u1eb1m tr\u00ean \u0111\u01b0\u1eddng th\u1eb3ng b <br\/> N\u00ean M $\\notin$ b v\u00e0 N $\\notin$ b <br\/> <span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0: C <\/span> ","column":2}]}],"id_ques":2053},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[4]],"list":[{"point":5,"ques":"\u0110\u01b0\u1eddng th\u1eb3ng d ch\u1ee9a \u0111i\u1ec3m P v\u00e0 \u0111i\u1ec3m Q nh\u01b0ng kh\u00f4ng ch\u1ee9a \u0111i\u1ec3m M. C\u00e1ch ghi n\u00e0o sau \u0111\u00e2y \u0111\u00fang?","select":["A. $P \\in d; Q \\notin d; M \\notin d$","B. $P \\in d; Q \\in d; M \\in d$","C. $P \\notin d; Q \\in d; M \\notin d$","D. $P \\in d; Q \\in d; M \\notin d$"],"hint":"","explain":" <span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span> Theo \u0111\u1ec1 b\u00e0i ta c\u00f3 h\u00ecnh v\u1ebd: <br\/> <center><img src='https://www.luyenthi123.com/file/luyenthi123/lop6/toan/hinhhoc/bai7/lv1/img\/H617_D121.png' \/><\/center><br\/> V\u00ec \u0111\u01b0\u1eddng th\u1eb3ng d ch\u1ee9a \u0111i\u1ec3m P v\u00e0 \u0111i\u1ec3m Q nh\u01b0ng kh\u00f4ng ch\u1ee9a \u0111i\u1ec3m M n\u00ean: <br\/> $ P \\in d; Q \\in d; M \\notin d$ <br\/> <span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0: D <\/span> ","column":2}]}],"id_ques":2054},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[2]],"list":[{"point":5,"ques":"Cho AB = 8cm. Tr\u00ean tia AB l\u1ea5y \u0111i\u1ec3m C sao cho AC = 2cm. Tr\u00ean tia BA l\u1ea5y \u0111i\u1ec3m D sao cho BD = 3cm. H\u00e3y so s\u00e1nh CB v\u00e0 AD.","select":["A. CB = AD","B. CB > AD","C. CB < AD"],"hint":"","explain":" <span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span> <br\/> <span class='basic_left'> <b> T\u00f3m t\u1eaft: <\/b> <br\/> Cho AB = 8cm <br\/> Tr\u00ean tia AB <br\/> AC = 2cm <br\/> Tr\u00ean tia BA <br\/> BD = 3cm <br\/> So s\u00e1nh CB v\u00e0 AD <\/span> <br\/> Theo \u0111\u1ec1 b\u00e0i ta c\u00f3 h\u00ecnh v\u1ebd: <br\/> <center><img src='https://www.luyenthi123.com/file/luyenthi123/lop6/toan/hinhhoc/bai7/lv1/img\/H617_D119.png' \/><\/center><br\/> Tr\u00ean tia AB c\u00f3: AC = 2cm; AB = 8cm <br\/> V\u00ec 2cm < 8cm n\u00ean AC < AB <br\/> $\\Rightarrow$ \u0110i\u1ec3m C n\u1eb1m gi\u1eefa hai \u0111i\u1ec3m A v\u00e0 B <br\/> $\\Rightarrow \\begin{align*} AC + CB &= AB \\\\ 2cm + CB &= 8cm \\\\ CB &= 8cm - 2cm \\\\ CB &= 6cm \\end{align*}$ <br\/> Tr\u00ean tia BD c\u00f3: BD = 3cm; BA = 8cm <br\/> V\u00ec 3cm < 8cm n\u00ean BD < BA <br\/> $\\Rightarrow$ \u0110i\u1ec3m D n\u1eb1m gi\u1eefa hai \u0111i\u1ec3m A v\u00e0 B <br\/> $\\Rightarrow \\begin{align*} BD + AD &= AB \\\\ 3cm + AD &= 8cm \\\\ AD &= 8cm - 3cm \\\\ AD &= 5cm \\end{align*}$ <br\/> V\u00ec CB = 6cm, AD = 5cm m\u00e0 6cm > 5cm n\u00ean CB > AD <br\/> <span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0: B <\/span> ","column":3}]}],"id_ques":2055},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[1]],"list":[{"point":5,"ques":"Cho AB = 4cm. Tr\u00ean tia \u0111\u1ed1i c\u1ee7a tia BA l\u1ea5y \u0111i\u1ec3m C sao cho BC = 5cm. Tr\u00ean tia \u0111\u1ed1i c\u1ee7a tia CB l\u1ea5y \u0111i\u1ec3m D sao cho CD = 4cm. H\u00e3y so s\u00e1nh AC v\u00e0 BD.","select":["A. AC = BD","B. AC > BD","C. AC < BD"],"hint":"","explain":" <span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span> <br\/> <span class='basic_left'> <b> T\u00f3m t\u1eaft: <\/b> <br\/> AB = 4cm <br\/> Tr\u00ean tia \u0111\u1ed1i c\u1ee7a tia BA <br\/> BC = 5cm <br\/> Tr\u00ean tia \u0111\u1ed1i c\u1ee7a tia CB <br\/> CD = 4cm <br\/> So s\u00e1nh AC v\u00e0 BD <\/span> <br\/> Theo \u0111\u1ec1 b\u00e0i ta c\u00f3 h\u00ecnh v\u1ebd: <br\/> <center><img src='https://www.luyenthi123.com/file/luyenthi123/lop6/toan/hinhhoc/bai7/lv1/img\/H617_D123.png' \/><\/center><br\/> V\u00ec tia BA v\u00e0 tia BC l\u00e0 hia tia \u0111\u1ed1i nhau n\u00ean \u0111i\u1ec3m B n\u1eb1m gi\u1eefa hai \u0111i\u1ec3m A v\u00e0 C <br\/> $ \\begin{align*} \\Rightarrow AC &= AB + BC \\\\ AC &= 4cm + 5cm \\\\ AC &= 9cm \\end{align*}$ <br\/> V\u00ec CB v\u00e0 CD l\u00e0 hai tia \u0111\u1ed1i nhau n\u00ean \u0111i\u1ec3m C n\u1eb1m gi\u1eefa hai \u0111i\u1ec3m B v\u00e0 D <br\/> $\\begin{align*} \\Rightarrow DB &= BC + CD \\\\ BD &= 5cm + 4cm \\\\ BD &= 9cm \\end{align*}$ <br\/> V\u00ec AC = 9cm, BD = 9cm m\u00e0 9cm = 9cm n\u00ean AC = BD <br\/> <span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0: A <\/span> ","column":3}]}],"id_ques":2056},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[2]],"list":[{"point":5,"ques":"3 \u0111i\u1ec3m A, B, C th\u1eb3ng h\u00e0ng n\u1ebfu:","select":["A. AB = 2,4cm; CB = 3,6cm; AC = 7cm","B. AB = 2,1cm; CA = 1,9cm; BC = 4cm","C. AB = 3,2cm; AC = 5cm; CA = 7,2cm","D. AC = 4cm; BC = 3cm; AB = 8cm"],"hint":"","explain":" <span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/> S\u1eed d\u1ee5ng t\u00ednh ch\u1ea5t c\u1ed9ng \u0111\u1ed9 d\u00e0i \u0111\u1ec3 ki\u1ec3m tra t\u1eebng \u0111\u00e1p \u00e1n<\/span> <br\/><br\/> <span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span> <br\/> +) V\u00ec AB = 2,4cm; CB = 3,6cm; Ac = 7cm <br\/> C\u00f3 AB + CB = 2,4cm + 3,6cm = 6cm <br\/> M\u00e0 6cm $\\neq$ 7cm n\u00ean 3 \u0111i\u1ec3m A, B, C kh\u00f4ng th\u1eb3ng h\u00e0ng <br\/> +) V\u00ec AB = 2,1cm; CA = 1,9cm; BC = 4cm <br\/> C\u00f3 AB + CA = 2,1cm + 1,9cm = 4cm <br\/> M\u00e0 4cm = 4cm n\u00ean 3 \u0111i\u1ec3m A, B, C th\u1eb3ng h\u00e0ng <br\/> +) V\u00ec AB = 3,2cm; AC = 5cm; CA = 7,2cm <br\/> C\u00f3 AB + AC = 3,2cm + 5cm = 8,2cm <br\/> M\u00e0 8,2cm $\\neq$ 7,2cm n\u00ean 3 \u0111i\u1ec3m A, B, C kh\u00f4ng th\u1eb3ng h\u00e0ng <br\/> +) V\u00ec AC = 4cm; BC = 3cm; AB = 8cm <br\/> C\u00f3 AC + BC = 7cm <br\/> M\u00e0 7cm $\\neq$ 8cm n\u00ean 3 \u0111i\u1ec3m A, B, C kh\u00f4ng th\u1eb3ng h\u00e0ng <br\/> <span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0: B <\/span> ","column":2}]}],"id_ques":2057},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[1]],"list":[{"point":5,"ques":"Bi\u1ebft IL = 2cm; LK = 5cm \u0111i\u1ec1u ki\u1ec7n \u0111\u1ec3 \u0111i\u1ec3m I n\u1eb1m gi\u1eefa hai \u0111i\u1ec3m L v\u00e0 K l\u00e0:","select":["A. IK = 3cm","B. IK = 2cm","C. IK = 5cm","D. IK = 7cm"],"hint":"","explain":" <span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/> \u0110\u1ec3 \u0111i\u1ec3m L n\u1eb1m gi\u1eefa hai \u0111i\u1ec3m I v\u00e0 K l\u00e0: IL + LK = IK <\/span> <br\/><br\/> <span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span> <br\/> \u0110i\u1ec1u ki\u1ec7n \u0111\u1ec3 \u0111i\u1ec3m L n\u1eb1m gi\u1eefa hai \u0111i\u1ec3m I v\u00e0 K l\u00e0: <br\/> $ \\begin{align*} IL + IK &= LK \\\\ 2cm + IK &= 5cm \\\\ IK &= 5cm - 2cm \\\\ IK &= 3cm \\end{align*}$ <br\/> V\u1eady \u0111i\u1ec1u ki\u1ec7n \u0111\u1ec3 \u0111i\u1ec3m L n\u1eb1m gi\u1eefa hai \u0111i\u1ec3m I v\u00e0 K l\u00e0 IK = 3cm <br\/> <span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0: A. IK = 3cm <\/span> ","column":2}]}],"id_ques":2058},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[4]],"list":[{"point":5,"ques":"Cho 3 \u0111i\u1ec3m A, B, C th\u1eb3ng h\u00e0ng, bi\u1ebft \u0111i\u1ec3m B n\u1eb1m gi\u1eefa hai \u0111i\u1ec3m A v\u00e0 C. Kh\u1eb3ng \u0111\u1ecbnh n\u00e0o sau \u0111\u00e2y \u0111\u00fang?","select":["A. Hai \u0111i\u1ec3m B v\u00e0 C n\u1eb1m kh\u00e1c ph\u00eda \u0111\u1ed1i v\u1edbi \u0111i\u1ec3m A","B. Hai \u0111i\u1ec3m A v\u00e0 C n\u1eb1m c\u00f9ng ph\u00eda \u0111\u1ed1i v\u1edbi \u0111i\u1ec3m B","C. Tia AC v\u00e0 tia CB l\u00e0 hai tia \u0111\u1ed1i nhau","D. Tia AB v\u00e0 tia AC l\u00e0 hai tia tr\u00f9ng nhau"],"hint":"","explain":" <span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span> <br\/> <center><img src='https://www.luyenthi123.com/file/luyenthi123/lop6/toan/hinhhoc/bai7/lv1/img\/H617_D126.png' \/><\/center> <br\/> V\u00ec \u0111i\u1ec3m B n\u1eb1m gi\u1eefa hai \u0111i\u1ec3m A v\u00e0 C <br\/> N\u00ean hai \u0111i\u1ec3m B v\u00e0 C n\u1eb1m c\u00f9ng ph\u00eda \u0111\u1ed1i v\u1edbi \u0111i\u1ec3m A <br\/> Hai \u0111i\u1ec3m A, C n\u1eb1m kh\u00e1c ph\u00eda \u0111\u1ed1i v\u1edbi \u0111i\u1ec3m B <br\/> Tia CA v\u00e0 tia CB l\u00e0 hai tia tr\u00f9ng nhau <br\/> Tia AB v\u00e0 tia AC l\u00e0 hai tia tr\u00f9ng nhau <br\/> <span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0: D <\/span> ","column":2}]}],"id_ques":2059},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[2]],"list":[{"point":5,"ques":"Cho \u0111i\u1ec3m M l\u00e0 trung \u0111i\u1ec3m c\u1ee7a \u0111o\u1ea1n th\u1eb3ng OA. Bi\u1ebft OA = 6cm. T\u00ednh MA.","select":["A. MA = 2cm","B. MA = 3cm","C. MA = 2,5cm","D. MA = 4cm"],"hint":"","explain":" <span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span> <br\/> V\u00ec \u0111i\u1ec3m M l\u00e0 trung \u0111i\u1ec3m c\u1ee7a \u0111o\u1ea1n th\u1eb3ng AB n\u00ean: <br\/> $OM = AM = \\dfrac{AB}{2} = \\dfrac{6cm}{2} = 3cm$ <br\/> <span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0: B. MA = 3cm <\/span> ","column":2}]}],"id_ques":2060}],"lesson":{"save":0,"level":1}}