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{"segment":[{"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":" <span class='basic_left'> H\u00ecnh ch\u1eef nh\u1eadt l\u00e0: <\/span>","select":["A. T\u1ee9 gi\u00e1c c\u00f3 m\u1ed9t g\u00f3c vu\u00f4ng","B. T\u1ee9 gi\u00e1c c\u00f3 hai g\u00f3c vu\u00f4ng","C. T\u1ee9 gi\u00e1c c\u00f3 ba g\u00f3c vu\u00f4ng","D. C\u1ea3 ba c\u00e2u tr\u00ean \u0111\u1ec1u sai"],"explain":" <span class='basic_left'> H\u00ecnh ch\u1eef nh\u1eadt l\u00e0 t\u1ee9 gi\u00e1c c\u00f3 ba g\u00f3c vu\u00f4ng. <center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/hinhhoc/bai6/lv1/img\/H816_D1_1.jpg' \/><\/center> <br\/> <span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n l\u00e0 C. <\/span><\/span> ","column":2}]}],"id_ques":1431},{"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":" <span class='basic_left'> H\u00ecnh b\u00ecnh h\u00e0nh $ABCD$ l\u00e0 h\u00ecnh ch\u1eef nh\u1eadt khi: <\/span>","select":["A. $AB=BC$","B. $AC=BD$","C. $BC=CD$","D. $AC\\bot BD$"],"explain":" <span class='basic_left'> Theo d\u1ea5u hi\u1ec7u nh\u1eadn bi\u1ebft, h\u00ecnh b\u00ecnh h\u00e0nh c\u00f3 hai \u0111\u01b0\u1eddng ch\u00e9o b\u1eb1ng nhau l\u00e0 h\u00ecnh ch\u1eef nh\u1eadt. T\u1ee9c l\u00e0: h\u00ecnh b\u00ecnh h\u00e0nh $ABCD$ l\u00e0 h\u00ecnh ch\u1eef nh\u1eadt khi: $AC=BD$ <center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/hinhhoc/bai6/lv1/img\/H816_D1_2.jpg' \/><\/center> <br\/> <span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n l\u00e0 B. <\/span><\/span> ","column":2}]}],"id_ques":1432},{"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":" <span class='basic_left'> Cho h\u00ecnh ch\u1eef nh\u1eadt c\u00f3 c\u00e1c k\u00edch th\u01b0\u1edbc l\u00e0 $6\\, cm$ v\u00e0 $8\\, cm$. Khi \u0111\u00f3 \u0111\u1ed9 d\u00e0i \u0111\u01b0\u1eddng ch\u00e9o h\u00ecnh ch\u1eef nh\u1eadt l\u00e0: <\/span>","select":["A. $10\\, cm$","B. $9\\, cm$","C. $12\\, cm$","D. $14\\, cm$"],"explain":" <span class='basic_left'> <center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/hinhhoc/bai6/lv1/img\/H816_D1_3.jpg' \/><\/center> X\u00e9t h\u00ecnh ch\u1eef nh\u1eadt $ABCD$ c\u00f3: $AB=8\\, cm; BC=6\\, cm$ <br\/> Tam gi\u00e1c $ABC$ vu\u00f4ng t\u1ea1i $B$ (t\u00ednh ch\u1ea5t h\u00ecnh ch\u1eef nh\u1eadt) <br\/> \u00c1p d\u1ee5ng \u0111\u1ecbnh l\u00fd Pi - ta - go v\u00e0o tam gi\u00e1c $ABC$ \u0111\u01b0\u1ee3c: <br\/> $AB^2+BC^2=AC^2$ <br\/> $\\Rightarrow AC^2=8^2+6^2=100$ <br\/> $\\Rightarrow AC=10\\, (cm)$ <br\/> <span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n l\u00e0 A. <\/span><\/span> ","column":2}]}],"id_ques":1433},{"time":24,"part":[{"title":"\u0110i\u1ec1n k\u1ebft qu\u1ea3 v\u00e0o \u00f4 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank","correct":[[["9"]]],"list":[{"point":5,"width":20,"type_input":"","ques":"<span class='basic_left'> Cho h\u00ecnh v\u1ebd sau: <center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/hinhhoc/bai6/lv1/img\/H816_D1_4.jpg' \/><\/center> Bi\u1ebft $ABCD$ l\u00e0 h\u00ecnh ch\u1eef nh\u1eadt. <br\/> T\u00ednh \u0111\u1ed9 d\u00e0i c\u1ea1nh $BC$. <br\/> <b> \u0110\u00e1p \u00e1n: <\/b> $BC=\\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{}\\, (cm)$ <\/span> ","explain":" <span class='basic_left'> <center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/hinhhoc/bai6/lv1/img\/H816_D1_4.jpg' \/><\/center> H\u00ecnh ch\u1eef nh\u1eadt $ABCD$ c\u00f3: $AB=12\\, cm; AC=15\\, cm$ <br\/> Tam gi\u00e1c $ABC$ vu\u00f4ng t\u1ea1i $B$. (t\u00ednh ch\u1ea5t h\u00ecnh ch\u1eef nh\u1eadt) <br\/> \u00c1p d\u1ee5ng \u0111\u1ecbnh l\u00fd Pi - ta - go v\u00e0o tam gi\u00e1c $ABC$ \u0111\u01b0\u1ee3c: <br\/> $AB^2+BC^2=AC^2$ <br\/> $\\Rightarrow BC^2=AC^2-AB^2$ <br\/> $\\Rightarrow BC^2=15^2-12^2=81$ <br\/> $\\Rightarrow BC=9\\, (cm)$ <br\/> <span class='basic_pink'> V\u1eady c\u1ea7n \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u00e0 $9$. <\/span> <\/span> "}]}],"id_ques":1434},{"time":24,"part":[{"title":"\u0110i\u1ec1n k\u1ebft qu\u1ea3 v\u00e0o \u00f4 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank","correct":[[["11"]]],"list":[{"point":5,"width":20,"type_input":"","ques":"<span class='basic_left'> Cho h\u00ecnh v\u1ebd sau: <center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/hinhhoc/bai6/lv1/img\/H816_D1_5.jpg' \/><\/center> Bi\u1ebft $ABCD$ l\u00e0 h\u00ecnh ch\u1eef nh\u1eadt. <br\/> T\u00ednh \u0111\u1ed9 d\u00e0i \u0111\u01b0\u1eddng ch\u00e9o $BD$. <br\/> <b> \u0110\u00e1p \u00e1n: <\/b> $BD=\\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{}\\, cm$ <\/span> ","explain":" <span class='basic_left'> <center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/hinhhoc/bai6/lv1/img\/H816_D1_5.jpg' \/><\/center> H\u00ecnh ch\u1eef nh\u1eadt $ABCD$ c\u00f3: $AB=6\\sqrt{2} \\, cm; AD=7\\, cm$ <br\/> Tam gi\u00e1c $ABD$ vu\u00f4ng t\u1ea1i $A$ (t\u00ednh ch\u1ea5t h\u00ecnh ch\u1eef nh\u1eadt) <br\/> \u00c1p d\u1ee5ng \u0111\u1ecbnh l\u00fd Pi - ta - go v\u00e0o tam gi\u00e1c $ABD$ \u0111\u01b0\u1ee3c: <br\/> $AB^2+AD^2=BD^2$ <br\/> $\\Rightarrow BD^2=(6\\sqrt{2})^2+7^2$ <br\/> $\\Rightarrow BD^2=121$ <br\/> $\\Rightarrow BD=11\\, (cm)$ <br\/> <span class='basic_pink'> V\u1eady c\u1ea7n \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u00e0 $11$. <\/span> <\/span> "}]}],"id_ques":1435},{"time":24,"part":[{"title":"\u0110i\u1ec1n k\u1ebft qu\u1ea3 v\u00e0o \u00f4 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank","correct":[[["14"]]],"list":[{"point":5,"width":20,"type_input":"","ques":"<span class='basic_left'> Cho h\u00ecnh v\u1ebd sau: <center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/hinhhoc/bai6/lv1/img\/H816_D1_6.jpg' \/><\/center>Bi\u1ebft $ABCD$ l\u00e0 h\u00ecnh ch\u1eef nh\u1eadt. <br\/> T\u00ednh chu vi c\u1ee7a h\u00ecnh ch\u1eef nh\u1eadt $ABCD$. <br\/> <b> \u0110\u00e1p \u00e1n: <\/b> $\\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{}\\, (cm)$ <\/span> ","hint":" Chu vi c\u1ee7a h\u00ecnh ch\u1eef nh\u1eadt b\u1eb1ng hai l\u1ea7n t\u1ed5ng hai k\u00edch th\u01b0\u1edbc c\u1ee7a n\u00f3.","explain":" <span class='basic_left'> <center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/hinhhoc/bai6/lv1/img\/H816_D1_6.jpg' \/><\/center> H\u00ecnh ch\u1eef nh\u1eadt $ABCD$ c\u00f3: $BD=5 \\, cm; BC=4\\, cm$ <br\/> Tam gi\u00e1c $BDC$ vu\u00f4ng t\u1ea1i $C$ (t\u00ednh ch\u1ea5t h\u00ecnh ch\u1eef nh\u1eadt) <br\/> \u00c1p d\u1ee5ng \u0111\u1ecbnh l\u00fd Pi - ta - go v\u00e0o tam gi\u00e1c $BDC$ \u0111\u01b0\u1ee3c: <br\/> $BC^2+DC^2=BD^2$ <br\/> $\\Rightarrow DC^2=BD^2-BC^2=5^2-4^2$ <br\/> $\\Rightarrow DC^2=9$ <br\/> $\\Rightarrow DC=3\\, (cm)$ <br\/> Chu vi c\u1ee7a h\u00ecnh ch\u1eef nh\u1eadt $ABCD$ l\u00e0: <br\/> $2(4+3)=14\\, (cm)$ <br\/> <span class='basic_pink'> V\u1eady c\u1ea7n \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u00e0 $14$. <\/span> <\/span> "}]}],"id_ques":1436},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t <br\/> Kh\u1eb3ng \u0111\u1ecbnh sau \u0111\u00e2y \u0111\u00fang hay sai","title_trans":"","temp":"multiple_choice","correct":[[1]],"list":[{"point":5,"ques":" <span class='basic_left'> H\u00ecnh thang c\u00f3 hai g\u00f3c \u1edf \u0111\u00e1y b\u1eb1ng nhau v\u00e0 trong c\u00e1c g\u00f3c c\u00f3 m\u1ed9t g\u00f3c vu\u00f4ng l\u00e0 h\u00ecnh ch\u1eef nh\u1eadt. <\/span>","select":[" \u0110\u00fang"," Sai"],"explain":" <span class='basic_left'> H\u00ecnh thang c\u00f3 hai g\u00f3c \u1edf \u0111\u00e1y b\u1eb1ng nhau l\u00e0 h\u00ecnh thang c\u00e2n <br\/> M\u00e0 h\u00ecnh thang c\u00e2n c\u00f3 m\u1ed9t trong c\u00e1c g\u00f3c l\u00e0 g\u00f3c vu\u00f4ng th\u00ec n\u00f3 l\u00e0 h\u00ecnh ch\u1eef nh\u1eadt. <br\/> <span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n l\u00e0 \u0110\u00fang. <\/span><\/span> ","column":2}]}],"id_ques":1437},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t <br\/> Kh\u1eb3ng \u0111\u1ecbnh sau \u0111\u00e2y \u0111\u00fang hay sai","title_trans":"","temp":"multiple_choice","correct":[[2]],"list":[{"point":5,"ques":" <span class='basic_left'> H\u00ecnh thang vu\u00f4ng c\u0169ng l\u00e0 m\u1ed9t h\u00ecnh ch\u1eef nh\u1eadt. <\/span>","select":[" \u0110\u00fang"," Sai"],"explain":" <span class='basic_left'> Kh\u1eb3ng \u0111\u1ecbnh tr\u00ean l\u00e0 sai. <br\/> <span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n l\u00e0 Sai. <\/span><\/span> ","column":2}]}],"id_ques":1438},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t <br\/> Kh\u1eb3ng \u0111\u1ecbnh sau \u0111\u00e2y \u0111\u00fang hay sai","title_trans":"","temp":"multiple_choice","correct":[[2]],"list":[{"point":5,"ques":" <span class='basic_left'> H\u00ecnh b\u00ecnh h\u00e0nh c\u00f3 hai c\u1ea1nh k\u1ec1 b\u1eb1ng nhau l\u00e0 h\u00ecnh ch\u1eef nh\u1eadt.<\/span>","select":[" \u0110\u00fang"," Sai"],"explain":" <span class='basic_left'> H\u00ecnh b\u00ecnh h\u00e0nh c\u00f3 m\u1ed9t g\u00f3c vu\u00f4ng l\u00e0 h\u00ecnh ch\u1eef nh\u1eadt. <br\/> <span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n l\u00e0 Sai. <\/span><\/span> ","column":2}]}],"id_ques":1439},{"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":" <span class='basic_left'> H\u00ecnh ch\u1eef nh\u1eadt c\u00f3 bao nhi\u00eau t\u00e2m \u0111\u1ed1i x\u1ee9ng? <\/span>","select":["A. 1","B. 2","C. 3","D. 4"],"explain":" <span class='basic_left'> <center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/hinhhoc/bai6/lv1/img\/H816_D1_2.jpg' \/><\/center> H\u00ecnh ch\u1eef nh\u1eadt c\u00f3 m\u1ed9t t\u00e2m \u0111\u1ed1i x\u1ee9ng l\u00e0 giao c\u1ee7a hai \u0111\u01b0\u1eddng ch\u00e9o. <br\/> <span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n l\u00e0 A. <\/span><\/span> ","column":4}]}],"id_ques":1440},{"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":" <span class='basic_left'> Cho h\u00ecnh b\u00ecnh h\u00e0nh $ABCD$. Ph\u00e2n gi\u00e1c c\u1ee7a g\u00f3c $A$ c\u1eaft ph\u00e2n gi\u00e1c c\u00e1c g\u00f3c $B$ v\u00e0 $D$ l\u1ea7n l\u01b0\u1ee3t t\u1ea1i $H$ v\u00e0 $G$, ph\u00e2n gi\u00e1c g\u00f3c $C$ c\u1eaft ph\u00e2n gi\u00e1c g\u00f3c $D$ v\u00e0 $B$ l\u1ea7n l\u01b0\u1ee3t t\u1ea1i $E$ v\u00e0 $F$. <br\/> T\u1ee9 gi\u00e1c $EFGH$ l\u00e0 h\u00ecnh g\u00ec?<\/span>","select":["A. H\u00ecnh thang c\u00e2n","B. H\u00ecnh b\u00ecnh h\u00e0nh","C. H\u00ecnh ch\u1eef nh\u1eadt"],"hint":"X\u00e9t tam gi\u00e1c $DEC$ v\u00e0 t\u00ednh g\u00f3c $E$. ","explain":" <span class='basic_left'> <center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/hinhhoc/bai6/lv1/img\/H816_D1_7.jpg' \/><\/center> Ta c\u00f3: <br\/> $\\widehat{{{D}_{1}}}=\\widehat{{{D}_{2}}};\\,\\,\\widehat{{{C}_{1}}}=\\widehat{{{C}_{2}}}$ (gi\u1ea3 thi\u1ebft) <br\/> M\u00e0 $AD\/\/ BC$ (t\u00ednh ch\u1ea5t) <br\/> $\\Rightarrow \\widehat{D}+\\widehat{C}={{180}^{o}}$ (trong c\u00f9ng ph\u00eda b\u00f9 nhau)<br\/> $\\Rightarrow 2\\left( \\widehat{{{D}_{1}}}+\\widehat{{{C}_{1}}} \\right)={{180}^{o}}\\Rightarrow \\widehat{{{D}_{1}}}+\\widehat{{{C}_{1}}}={{90}^{o}}$<br\/> X\u00e9t $\\Delta DEC:\\,\\,\\widehat{{{D}_{1}}}+\\widehat{{{C}_{1}}}+\\widehat{E_{1}}={{180}^{o}}\\Rightarrow \\widehat{E_{1}}={{90}^{o}}$<br\/> T\u01b0\u01a1ng t\u1ef1 ta ch\u1ee9ng minh \u0111\u01b0\u1ee3c $\\widehat{H_{1}}={{90}^{o}};\\widehat{G_{1}}={{90}^{o}}$ <br\/> X\u00e9t t\u1ee9 gi\u00e1c $EFGH$ ta c\u00f3: $\\widehat{E_{1}}=\\widehat{H_{1}}=\\widehat{G_{1}}={{90}^{o}}$<br\/>$\\Rightarrow $ T\u1ee9 gi\u00e1c $EFGH$ l\u00e0 h\u00ecnh ch\u1eef nh\u1eadt (d\u1ea5u hi\u1ec7u nh\u1eadn bi\u1ebft). <br\/> <span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n l\u00e0 C. <\/span><\/span> ","column":3}]}],"id_ques":1441},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t <br\/> Kh\u1eb3ng \u0111\u1ecbnh sau \u0111\u00e2y \u0111\u00fang hay sai","title_trans":"","temp":"multiple_choice","correct":[[1]],"list":[{"point":5,"ques":" <span class='basic_left'> Trong tam gi\u00e1c vu\u00f4ng, \u0111\u01b0\u1eddng trung tuy\u1ebfn \u1ee9ng v\u1edbi c\u1ea1nh huy\u1ec1n b\u1eb1ng m\u1ed9t n\u1eeda c\u1ea1nh huy\u1ec1n. <\/span>","select":[" \u0110\u00fang"," Sai"],"explain":" <span class='basic_left'> <center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/hinhhoc/bai6/lv1/img\/H816_D1_8.jpg' \/><\/center> Kh\u1eb3ng \u0111\u1ecbnh tr\u00ean l\u00e0 <b> \u0111\u00fang<\/b>. <br\/> <span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n l\u00e0 \u0110\u00fang. <\/span><\/span> ","column":2}]}],"id_ques":1442},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":" \u0110\u1ec1 chung cho hai c\u00e2u","temp":"multiple_choice","correct":[[1]],"list":[{"point":5,"ques":" <span class='basic_left'> <center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/hinhhoc/bai6/lv1/img\/H816_D1_9.jpg' \/><\/center> Cho h\u00ecnh v\u1ebd nh\u01b0 tr\u00ean. <br\/> <b> C\u00e2u 1:<\/b> $\\Delta ABF$ v\u00e0 $\\Delta ACF$ l\u00e0 c\u00e1c tam gi\u00e1c g\u00ec? <\/span>","select":["A. Tam gi\u00e1c c\u00e2n","B. Tam gi\u00e1c vu\u00f4ng","C. Tam gi\u00e1c \u0111\u1ec1u"],"explain":" <span class='basic_left'> <center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/hinhhoc/bai6/lv1/img\/H816_D1_9.jpg' \/><\/center> Do $\\Delta ABC$ vu\u00f4ng t\u1ea1i $A$ v\u00e0 $AF$ l\u00e0 \u0111\u01b0\u1eddng trung tuy\u1ebfn \u1ee9ng v\u1edbi c\u1ea1nh \u0111\u00e1y $BC$. <br\/> $\\Rightarrow AF=BF=CF$ <br\/> Do \u0111\u00f3 c\u00e1c tam gi\u00e1c $ABF$ v\u00e0 $ACF$ l\u00e0 c\u00e1c tam gi\u00e1c c\u00e2n. <br\/> <span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n l\u00e0 A. <\/span><\/span> ","column":3}]}],"id_ques":1443},{"time":24,"part":[{"title":"\u0110i\u1ec1n k\u1ebft qu\u1ea3 v\u00e0o \u00f4 tr\u1ed1ng","title_trans":"\u0110\u1ec1 chung cho hai c\u00e2u","temp":"fill_the_blank","correct":[[["14"]]],"list":[{"point":5,"width":20,"type_input":"","ques":"<span class='basic_left'> <center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/hinhhoc/bai6/lv1/img\/H816_D1_9.jpg' \/><\/center> Cho h\u00ecnh v\u1ebd nh\u01b0 tr\u00ean. <br\/> <b> C\u00e2u 2:<\/b> Cho $AF=7\\, cm$ th\u00ec \u0111\u1ed9 d\u00e0i c\u1ea1nh $BC$ l\u00e0 $\\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{}$ $(cm)$ <\/span> ","explain":" <span class='basic_left'> <center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/hinhhoc/bai6/lv1/img\/H816_D1_9.jpg' \/><\/center> Theo c\u00e2u 1, ta \u0111\u00e3 ch\u1ec9 ra: $AF=BF=CF$ <br\/> T\u1ee9c l\u00e0: $BC=2AF=2.7=14\\, (cm)$ <br\/> <span class='basic_pink'> V\u1eady c\u1ea7n \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u00e0 $14$. <\/span> <\/span> "}]}],"id_ques":1444},{"time":24,"part":[{"title":"\u0110i\u1ec1n k\u1ebft qu\u1ea3 v\u00e0o \u00f4 tr\u1ed1ng","title_trans":"\u0110\u1ec1 chung cho hai c\u00e2u","temp":"fill_the_blank","correct":[[["="]]],"list":[{"point":5,"width":20,"type_input":"","ques":"<span class='basic_left'> <center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/hinhhoc/bai6/lv1/img\/H816_D1_10.jpg' \/><\/center> Cho h\u00ecnh v\u1ebd nh\u01b0 tr\u00ean. <br\/> Bi\u1ebft $\\widehat{A}=90^o$; $BM=CM$ <br\/> <b> C\u00e2u 1:<\/b> So s\u00e1nh hai g\u00f3c $\\widehat{BAH}$ v\u00e0 $\\widehat{MCA}$. <br\/><br\/> <b> \u0110\u00e1p \u00e1n: <\/b> $\\widehat{BAH}\\, \\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{} \\,\\widehat{MCA}$ <\/span> ","explain":" <span class='basic_left'> <center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/hinhhoc/bai6/lv1/img\/H816_D1_10.jpg' \/><\/center> Do $\\Delta ABC$ vu\u00f4ng t\u1ea1i $A$ n\u00ean: <br\/> $\\widehat{MCA}=90^o-\\widehat{B}$ <br\/> $\\Delta ABH$ vu\u00f4ng t\u1ea1i $H$ n\u00ean: <br\/> $\\widehat{BAH}=90^o-\\widehat{B}$ <br\/> Do \u0111\u00f3: $\\widehat{BAH}=\\widehat{MCA}$. <br\/> <span class='basic_pink'> V\u1eady c\u1ea7n \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u00e0 d\u1ea5u $=$. <\/span> <\/span> "}]}],"id_ques":1445},{"time":24,"part":[{"title":"\u0110i\u1ec1n k\u1ebft qu\u1ea3 v\u00e0o \u00f4 tr\u1ed1ng","title_trans":"\u0110\u1ec1 chung cho hai c\u00e2u","temp":"fill_the_blank","correct":[[["="]]],"list":[{"point":5,"width":20,"type_input":"","ques":"<span class='basic_left'> <center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/hinhhoc/bai6/lv1/img\/H816_D1_10.jpg' \/><\/center> Cho h\u00ecnh v\u1ebd nh\u01b0 tr\u00ean. <br\/> Bi\u1ebft $\\widehat{A}=90^o$; $BM=CM$ <br\/> <b> C\u00e2u 2:<\/b> So s\u00e1nh hai g\u00f3c $\\widehat{CAH}$ v\u00e0 $\\widehat{MBA}$ <br\/><br\/> <b> \u0110\u00e1p \u00e1n: <\/b> $\\widehat{CAH}\\, \\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{} \\,\\widehat{MBA}$ <\/span> ","explain":" <span class='basic_left'> <center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/hinhhoc/bai6/lv1/img\/H816_D1_10.jpg' \/><\/center> Do $\\Delta ABC$ vu\u00f4ng t\u1ea1i $A$ n\u00ean: <br\/> $\\widehat{MBA}=90^o-\\widehat{C}$ <br\/> $\\Delta ACH$ vu\u00f4ng t\u1ea1i $H$ n\u00ean: <br\/> $\\widehat{CAH}=90^o-\\widehat{C}$ <br\/> Do \u0111\u00f3: $\\widehat{MBA}=\\widehat{CAH}$ <br\/> <span class='basic_pink'> V\u1eady c\u1ea7n \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u00e0 d\u1ea5u $=$. <\/span> <\/span> "}]}],"id_ques":1446},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":" \u0110\u1ec1 chung cho b\u1ed1n c\u00e2u","temp":"multiple_choice","correct":[[1]],"list":[{"point":5,"ques":" <span class='basic_left'> Cho $\\Delta ABC$ c\u00e2n \u1edf $A$ c\u00f3 $M$ v\u00e0 $N$ l\u1ea7n l\u01b0\u1ee3t l\u00e0 trung \u0111i\u1ec3m c\u1ee7a $BC$ v\u00e0 $AC$. \u0110\u01b0\u1eddng th\u1eb3ng $MN$ c\u1eaft \u0111\u01b0\u1eddng th\u1eb3ng song song v\u1edbi $BC$ k\u1ebb t\u1eeb $A$ t\u1ea1i \u0111i\u1ec3m $D$. <br\/> <b> C\u00e2u 1:<\/b> $\\Delta AND$ l\u00e0 tam gi\u00e1c c\u00e2n <b> \u0111\u00fang<\/b> hay <b>sai <\/b>?<\/span>","select":[" \u0110\u00fang"," Sai"],"explain":" <span class='basic_left'> <center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/hinhhoc/bai6/lv1/img\/H816_D1_11ab.jpg' \/><\/center> X\u00e9t $\\Delta ABC$ c\u00f3: $AN=CN; BM=CM$ <br\/> $\\Rightarrow MN$ l\u00e0 \u0111\u01b0\u1eddng trung b\u00ecnh c\u1ee7a $\\Delta ABC$. <br\/> $\\Rightarrow MN \/\/ AB$ n\u00ean $\\widehat{M_1}=\\widehat{B}$ (\u0111\u1ed3ng v\u1ecb) <br\/>M\u00e0 $\\widehat{B}=\\widehat{C}$ ($\\Delta ABC$ c\u00e2n t\u1ea1i $A$) <br\/> $\\Rightarrow \\widehat{M_1}=\\widehat{C}$ (1) <br\/> Do $AD \/\/ BC$ n\u00ean $\\widehat{ADN}=\\widehat{M_1}; \\widehat{DAN}=\\widehat{C}$ (so le trong) (2) <br\/> T\u1eeb (1) v\u00e0 (2) $\\Rightarrow \\widehat{ADN}=\\widehat{DAN}$ <br\/> $\\Rightarrow \\Delta AND$ c\u00e2n t\u1ea1i $N$. <br\/> <span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n l\u00e0 \u0110\u00fang. <\/span><\/span> ","column":2}]}],"id_ques":1447},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":" \u0110\u1ec1 chung cho b\u1ed1n c\u00e2u","temp":"multiple_choice","correct":[[3]],"list":[{"point":5,"ques":" <span class='basic_left'>Cho $\\Delta ABC$ c\u00e2n \u1edf $A$ c\u00f3 $M$ v\u00e0 $N$ l\u1ea7n l\u01b0\u1ee3t l\u00e0 trung \u0111i\u1ec3m c\u1ee7a $BC$ v\u00e0 $AC$. \u0110\u01b0\u1eddng th\u1eb3ng $MN$ c\u1eaft \u0111\u01b0\u1eddng th\u1eb3ng song song v\u1edbi $BC$ k\u1ebb t\u1eeb $A$ t\u1ea1i \u0111i\u1ec3m $D$. <br\/> <b> C\u00e2u 2:<\/b> T\u1ee9 gi\u00e1c $ABMD$ l\u00e0 h\u00ecnh g\u00ec?<\/span>","select":["A. H\u00ecnh ch\u1eef nh\u1eadt","B. H\u00ecnh thang","C. H\u00ecnh b\u00ecnh h\u00e0nh"],"explain":" <span class='basic_left'> <center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/hinhhoc/bai6/lv1/img\/H816_D1_11ab.jpg' \/><\/center> Theo c\u00e2u 1, ta ch\u1ec9 ra \u0111\u01b0\u1ee3c: $MD\/\/AB$ v\u00e0 $AD\/\/BM$ <br\/> Do \u0111\u00f3 t\u1ee9 gi\u00e1c $ABMD$ l\u00e0 h\u00ecnh b\u00ecnh h\u00e0nh (d\u1ea5u hi\u1ec7u nh\u1eadn bi\u1ebft). <br\/> <span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n l\u00e0 C. <\/span><\/span> ","column":3}]}],"id_ques":1448},{"time":24,"part":[{"title":"\u0110i\u1ec1n k\u1ebft qu\u1ea3 v\u00e0o \u00f4 tr\u1ed1ng","title_trans":"\u0110\u1ec1 chung cho b\u1ed1n c\u00e2u","temp":"fill_the_blank","correct":[[["="]]],"list":[{"point":5,"width":20,"type_input":"","ques":"<span class='basic_left'> Cho $\\Delta ABC$ c\u00e2n \u1edf $A$ c\u00f3 $M$ v\u00e0 $N$ l\u1ea7n l\u01b0\u1ee3t l\u00e0 trung \u0111i\u1ec3m c\u1ee7a $BC$ v\u00e0 $AC$. \u0110\u01b0\u1eddng th\u1eb3ng $MN$ c\u1eaft \u0111\u01b0\u1eddng th\u1eb3ng song song v\u1edbi $BC$ k\u1ebb t\u1eeb $A$ t\u1ea1i \u0111i\u1ec3m $D$. <br\/> <b> C\u00e2u 3:<\/b> So s\u00e1nh $MD$ v\u1edbi $AC$ <br\/><br\/> <b> \u0110\u00e1p \u00e1n: <\/b> $MD\\, \\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{} \\,AC$ <\/span> ","explain":" <span class='basic_left'> <center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/hinhhoc/bai6/lv1/img\/H816_D1_11ab.jpg' \/><\/center> Theo c\u00e2u 2, ta ch\u1ee9ng minh \u0111\u01b0\u1ee3c $ABMD$ l\u00e0 h\u00ecnh b\u00ecnh h\u00e0nh. <br\/> $\\Rightarrow AB=MD$ <br\/> M\u00e0 $AB=AC$ (gi\u1ea3 thi\u1ebft) n\u00ean $MD=AC$ <br\/> <span class='basic_pink'> V\u1eady c\u1ea7n \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u00e0 d\u1ea5u $=$. <\/span> <\/span> "}]}],"id_ques":1449},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":" \u0110\u1ec1 chung cho b\u1ed1n c\u00e2u","temp":"multiple_choice","correct":[[1]],"list":[{"point":5,"ques":" <span class='basic_left'>Cho $\\Delta ABC$ c\u00e2n \u1edf $A$ c\u00f3 $M$ v\u00e0 $N$ l\u1ea7n l\u01b0\u1ee3t l\u00e0 trung \u0111i\u1ec3m c\u1ee7a $BC$ v\u00e0 $AC$. \u0110\u01b0\u1eddng th\u1eb3ng $MN$ c\u1eaft \u0111\u01b0\u1eddng th\u1eb3ng song song v\u1edbi $BC$ k\u1ebb t\u1eeb $A$ t\u1ea1i \u0111i\u1ec3m $D$. <br\/> <b> C\u00e2u 4:<\/b> T\u1ee9 gi\u00e1c $ADCM$ l\u00e0 h\u00ecnh g\u00ec?<\/span>","select":["A. H\u00ecnh ch\u1eef nh\u1eadt","B. H\u00ecnh thang","C. H\u00ecnh b\u00ecnh h\u00e0nh"],"explain":" <span class='basic_left'> <center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/hinhhoc/bai6/lv1/img\/H816_D1_11d.jpg' \/><\/center> Theo c\u00e2u 3, ta ch\u1ee9ng minh \u0111\u01b0\u1ee3c: $AD \/\/ BM; AD = BM$ ($ABMD$ l\u00e0 h\u00ecnh b\u00ecnh h\u00e0nh) <br\/> M\u00e0 $BM=MC, M \\in BC$<br\/>$ \\Rightarrow AD = MC; AD \/\/ MC$ <br\/> Do \u0111\u00f3 $ADCM$ l\u00e0 h\u00ecnh b\u00ecnh h\u00e0nh (d\u1ea5u hi\u1ec7u nh\u1eadn bi\u1ebft) (1) <br\/> Tam gi\u00e1c $ABC$ c\u00e2n \u1edf $A$ v\u00e0 $AM$ l\u00e0 trung tuy\u1ebfn n\u00ean $AM$ c\u0169ng l\u00e0 \u0111\u01b0\u1eddng cao. <br\/> $\\Rightarrow AM \\bot BC$ hay $\\widehat{AMC}=90^o$ (2)<br\/> T\u1eeb (1) v\u00e0 (2) t\u1ee9 gi\u00e1c $ADCM$ l\u00e0 h\u00ecnh ch\u1eef nh\u1eadt (d\u1ea5u hi\u1ec7u nh\u1eadn bi\u1ebft). <br\/> <span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n l\u00e0 A. <\/span><\/span>","column":3}]}],"id_ques":1450}],"lesson":{"save":0,"level":1}}

Điểm của bạn.

Câu hỏi này theo dạng chọn đáp án đúng, sau khi đọc xong câu hỏi, bạn bấm vào một trong số các đáp án mà chương trình đưa ra bên dưới, sau đó bấm vào nút gửi để kiểm tra đáp án và sẵn sàng chuyển sang câu hỏi kế tiếp

Trả lời đúng trong khoảng thời gian quy định bạn sẽ được + số điểm như sau:
Trong khoảng 1 phút đầu tiên + 5 điểm
Trong khoảng 1 phút -> 2 phút + 4 điểm
Trong khoảng 2 phút -> 3 phút + 3 điểm
Trong khoảng 3 phút -> 4 phút + 2 điểm
Trong khoảng 4 phút -> 5 phút + 1 điểm

Quá 5 phút: không được cộng điểm

Tổng thời gian làm mỗi câu (không giới hạn)

Điểm của bạn.

Bấm vào đây nếu phát hiện có lỗi hoặc muốn gửi góp ý