Tính chất tia phân giác của một góc. Tính chất ba đường phân giác của tam giác-level1

Home Lớp 7 Toán lớp 7 - Sách kết nối tri thức Tính chất tia phân giác của một góc. Tính chất ba đường phân giác của tam giácBài tập cơ bản

{"common":{"save":0,"post_id":"1356","level":1,"total":20,"point":5,"point_extra":0},"segment":[{"id":"1921","post_id":"1356","mon_id":"0","chapter_id":"0","question":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","options":{"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 $\\triangle{MNP}$, c\u00e1c \u0111\u01b0\u1eddng ph\u00e2n gi\u00e1c $MD; NE$ c\u1eaft nhau \u1edf $I$. Trong c\u00e1c kh\u1eb3ng \u0111\u1ecbnh sau kh\u1eb3ng \u0111\u1ecbnh n\u00e0o \u0111\u00fang? ","select":[" A. \u0110i\u1ec3m $I$ c\u00e1ch \u0111\u1ec1u $3$ \u0111\u1ec9nh c\u1ee7a tam gi\u00e1c <\/span> "," B. \u0110i\u1ec3m $I$ c\u00e1ch \u0111\u1ec1u $3$ c\u1ea1nh c\u1ee7a tam gi\u00e1c <\/span>"," C. $MI = \\dfrac{2}{3}MD$ <\/span> "],"hint":"","explain":" <center><img src='img\/H7C3B21_D01.png' \/><\/center> <br\/> Theo t\u00ednh ch\u1ea5t ba \u0111\u01b0\u1eddng ph\u00e2n gi\u00e1c c\u1ee7a tam gi\u00e1c th\u00ec: <br\/> Ba \u0111\u01b0\u1eddng ph\u00e2n gi\u00e1c c\u00f9ng \u0111i qua m\u1ed9t \u0111i\u1ec3m. \u0110i\u1ec3m n\u00e0y c\u00e1ch \u0111\u1ec1u ba c\u1ea1nh c\u1ee7a tam gi\u00e1c \u0111\u00f3 <br\/> V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0: B <\/span>","column":1}]}]},"correct":"","level":"1","hint":"","answer":"","type":"json","extra_type":"","time":"0","user_id":"0","test":"0","date":"2019-09-30 09:23:05"},{"id":"1922","post_id":"1356","mon_id":"0","chapter_id":"0","question":"Ch\u1ecdn nh\u1eefng<\/u> \u0111\u00e1p \u00e1n \u0111\u00fang","options":{"time":24,"part":[{"title":"Ch\u1ecdn nh\u1eefng<\/u> \u0111\u00e1p \u00e1n \u0111\u00fang","title_trans":"Ch\u1ecdn \u0111\u01b0\u1ee3c nhi\u1ec1u \u0111\u00e1p \u00e1n","temp":"checkbox","correct":[["2","3","4"]],"list":[{"point":5,"img":"","ques":"Ch\u1ecdn c\u00e1c kh\u1eb3ng \u0111\u1ecbnh \u0111\u00fang trong c\u00e1c kh\u1eb3ng \u0111\u1ecbnh sau:","hint":"","column":1,"number_true":3,"select":["A. \u0110i\u1ec3m c\u00e1ch \u0111\u1ec1u hai \u0111\u01b0\u1eddng th\u1eb3ng ch\u1ee9a hai c\u1ea1nh c\u1ee7a m\u1ed9t g\u00f3c th\u00ec n\u1eb1m tr\u00ean tia ph\u00e2n gi\u00e1c c\u1ee7a g\u00f3c \u0111\u00f3.","B. \u0110i\u1ec3m n\u1eb1m trong tam gi\u00e1c v\u00e0 c\u00e1ch \u0111\u1ec1u ba c\u1ea1nh c\u1ee7a tam gi\u00e1c l\u00e0 giao \u0111i\u1ec3m ba \u0111\u01b0\u1eddng ph\u00e2n gi\u00e1c c\u1ee7a tam gi\u00e1c \u0111\u00f3","C. \u0110i\u1ec3m c\u00e1ch \u0111\u1ec1u ba \u0111\u01b0\u1eddng th\u1eb3ng ch\u1ee9a ba c\u1ea1nh c\u1ee7a m\u1ed9t tam gi\u00e1c lu\u00f4n n\u1eb1m trong tam gi\u00e1c \u0111\u00f3.","D. \u0110i\u1ec3m n\u1eb1m tr\u00ean \u0111\u01b0\u1eddng ph\u00e2n gi\u00e1c c\u1ee7a g\u00f3c th\u00ec c\u00e1ch \u0111\u1ec1u hai c\u1ea1nh c\u1ee7a g\u00f3c "],"explain":" A - SAI theo t\u00ednh ch\u1ea5t tia ph\u00e2n gi\u00e1c c\u1ee7a g\u00f3c (\u0111i\u1ec3m \u0111\u00f3 ph\u1ea3i n\u1eb1m b\u00ean trong g\u00f3c) <br\/> B - \u0110\u00daNG theo t\u00ednh ch\u1ea5t ba \u0111\u01b0\u1eddng ph\u00e2n gi\u00e1c trong tam gi\u00e1c <br\/> C - \u0110\u00daNG <br\/> D - \u0110\u00daNG theo t\u00ednh ch\u1ea5t tia ph\u00e2n gi\u00e1c c\u1ee7a g\u00f3c <\/span>"}]}]},"correct":"","level":"1","hint":"","answer":"","type":"json","extra_type":"","time":"0","user_id":"0","test":"0","date":"2019-09-30 09:23:05"},{"id":"1923","post_id":"1356","mon_id":"0","chapter_id":"0","question":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","options":{"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":"G\u1ecdi $I$ l\u00e0 giao \u0111i\u1ec3m ba \u0111\u01b0\u1eddng ph\u00e2n gi\u00e1c trong tam gi\u00e1c $DEF$ \u0111\u1ec1u. Trong c\u00e1c kh\u1eb3ng \u0111\u1ecbnh sau kh\u1eb3ng \u0111\u1ecbnh n\u00e0o sai? ","select":[" A. Giao \u0111i\u1ec3m $DI$ v\u1edbi $EF$ l\u00e0 $M$ th\u00ec $DM$ l\u00e0 \u0111\u01b0\u1eddng ph\u00e2n gi\u00e1c v\u00e0 l\u00e0 \u0111\u01b0\u1eddng trung tuy\u1ebfn \u1ee9ng v\u1edbi c\u1ea1nh $EF$ <\/span> "," B. G\u1ecdi giao \u0111i\u1ec3m $DI$ v\u1edbi $EF$ l\u00e0 $M$ th\u00ec $IM = \\dfrac{2}{3}DM$ <\/span>"," C. $I$ l\u00e0 tr\u1ecdng t\u00e2m tam gi\u00e1c $DEF$ <\/span>"," D. $I$ c\u00e1ch \u0111\u1ec1u $3$ c\u1ea1nh c\u1ee7a tam gi\u00e1c <\/span>"],"hint":"","explain":" H\u01b0\u1edbng d\u1eabn:<\/span><br\/> A - Ch\u1ee9ng minh $EM = FM$ b\u1eb1ng c\u00e1ch x\u00e9t $\\triangle{FDM}$ v\u00e0 $\\triangle{EDM}$ <br\/> B - Ch\u1ec9 ra \u0111\u00e2u l\u00e0 tr\u1ecdng t\u00e2m v\u00e0 d\u1ef1a v\u00e0o t\u00ednh ch\u1ea5t tr\u1ecdng t\u00e2m <br\/><br\/>B\u00e0i gi\u1ea3i:<\/span><br\/> <center><img src='img\/H7C3B21_D02.png' \/><\/center> <br\/> $\\blacktriangleright$ A - \u0110\u00fang v\u00ec: <br\/> X\u00e9t $\\triangle{FDM}$ v\u00e0 $\\triangle{EDM}$ c\u00f3: <br\/> $\\begin{cases} DF = DE (\\triangle{DEF} \\hspace{0,2cm} \\text{\u0111\u1ec1u}) \\\\ \\widehat{FDM} = \\widehat{EDM} (gt) \\\\ DM \\hspace{0,2cm} \\text{chung} \\end{cases}$ <br\/> $\\Rightarrow$ $\\triangle{FDM} = \\widehat{EDM}$ (c.g.c) <br\/> $\\Rightarrow$ $EM = FM$ hay $DM$ l\u00e0 trung tuy\u1ebfn \u1ee9ng v\u1edbi c\u1ea1nh $EF$ <br\/> $\\blacktriangleright$ SAI v\u00ec: <br\/> Theo c\u00e2u tr\u00ean $DM$ l\u00e0 trung tuy\u1ebfn <br\/> Ch\u1ee9ng minh t\u01b0\u01a1ng t\u1ef1 ta c\u00f3 $FI$ v\u00e0 $EI$ c\u0169ng l\u00e0 trung tuy\u1ebfn c\u1ee7a tam gi\u00e1c $DEF$ <br\/> $\\Rightarrow$ $I$ l\u00e0 tr\u1ecdng t\u00e2m tam gi\u00e1c $DEF$ <br\/> Theo t\u00ednh ch\u1ea5t tr\u1ecdng t\u00e2m: $DI = \\dfrac{2}{3}DM$ $\\Rightarrow$ $IM = \\dfrac{1}{3}DM$ <br\/> $\\blacktriangleright$ C - \u0110\u00fang (cmt) <br\/> $\\blacktriangleright$ D - \u0110\u00fang theo t\u00ednh ch\u1ea5t ba \u0111\u01b0\u1eddng ph\u00e2n gi\u00e1c trong tam gi\u00e1c <br\/> V\u1eady \u0111\u00e1p \u00e1n sai l\u00e0: B <\/span>","column":1}]}]},"correct":"","level":"1","hint":"","answer":"","type":"json","extra_type":"","time":"0","user_id":"0","test":"0","date":"2019-09-30 09:23:05"}]}