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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":10,"ques":" <span class='basic_left'> Cho $\\Delta ABC$ v\u1edbi ba trung tuy\u1ebfn $AM, BN$ v\u00e0 $CP$ \u0111\u1ed3ng quy t\u1ea1i $G$. \u0110i\u1ec3m $E$ v\u00e0 $F$ l\u1ea7n l\u01b0\u1ee3t l\u00e0 trung \u0111i\u1ec3m c\u1ee7a $GB$ v\u00e0 $GC$. \u0110\u1ec3 $NFEP$ l\u00e0 h\u00ecnh ch\u1eef nh\u1eadt th\u00ec: <\/span>","select":["A. $\\Delta ABC$ c\u00f3 $\\widehat{A}=60^o$","B. $\\Delta ABC$ c\u00f3 $\\widehat{A}=30^o$","C. $\\Delta ABC$ c\u00e2n t\u1ea1i $A$","D. $\\Delta ABC$ c\u00f3 $\\widehat{A}=90^o$"],"hint":" T\u1eeb $E$ k\u1ebb $EG\\bot BF$ <br\/> $EG$ ch\u00ednh l\u00e0 kho\u1ea3ng c\u00e1ch gi\u1eefa hai \u0111\u01b0\u1eddng th\u1eb3ng $DE$ v\u00e0 $BF$ c\u1ea7n t\u00ednh","explain":" <span class='basic_left'> <center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/hinhhoc/bai6/lv3/img\/H816_K1_1.jpg' \/><\/center> Trong $\\Delta ABC$ c\u00f3: $AP=PB; AN=NC$ <br\/> $\\Rightarrow PN$ l\u00e0 \u0111\u01b0\u1eddng trung b\u00ecnh c\u1ee7a $\\Delta ABC$. <br\/> $\\Rightarrow PN \/\/BC; PN=\\dfrac{1}{2}BC$ (1) <br\/> X\u00e9t $\\Delta BGC$ c\u00f3: $BE=EG; CF=GF$ <br\/> $\\Rightarrow EF$ l\u00e0 \u0111\u01b0\u1eddng trung b\u00ecnh c\u1ee7a $\\Delta BGC$. <br\/> $\\Rightarrow EF\/\/BC; EF=\\dfrac{1}{2}BC$ (2) <br\/> T\u1eeb (1) v\u00e0 (2) suy ra $PN = EF; PN\/\/ EF$ <br\/> Do \u0111\u00f3 t\u1ee9 gi\u00e1c $NFEP$ l\u00e0 h\u00ecnh b\u00ecnh h\u00e0nh (d\u1ea5u hi\u1ec7u nh\u1eadn bi\u1ebft). <br\/> X\u00e9t $\\Delta ABG$, ch\u1ee9ng minh t\u01b0\u01a1ng t\u1ef1 ta \u0111\u01b0\u1ee3c: <br\/> $PE \/\/AG \\Rightarrow PE \/\/ AM$ (3)<br\/> M\u00e0 $PN \/\/ BC$ (ch\u1ee9ng minh tr\u00ean) (4) <br\/> T\u1eeb (3) v\u00e0 (4) $\\Rightarrow$ $\\widehat{EPN}=\\widehat{AMB}$. <br\/> \u0110\u1ec3 $NFEP$ l\u00e0 h\u00ecnh ch\u1eef nh\u1eadt th\u00ec $PE\\bot PN$ hay $\\widehat{EPN}=90^o$. <br\/> $\\Rightarrow \\widehat{AMB}=90^o$ <br\/> $\\Rightarrow \\Delta ABC$ c\u00e2n t\u1ea1i $A$. <br\/> <span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n l\u00e0 C. <\/span><\/span> ","column":2}]}],"id_ques":1451},{"time":24,"part":[{"title":"\u0110i\u1ec1n k\u1ebft qu\u1ea3 v\u00e0o \u00f4 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank","correct":[[["25"]]],"list":[{"point":10,"width":20,"type_input":"","ques":"<span class='basic_left'> Cho h\u00ecnh ch\u1eef nh\u1eadt $MNPQ$, bi\u1ebft \u0111\u01b0\u1eddng ph\u00e2n gi\u00e1c g\u00f3c $M$ chia c\u1ea1nh $PQ$ th\u00e0nh hai \u0111o\u1ea1n th\u1eb3ng sao cho $PD=15\\, cm$ v\u00e0 $DQ=5\\, cm$. N\u1eeda chu vi c\u1ee7a h\u00ecnh ch\u1eef nh\u1eadt $MNPQ$ 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/lv3/img\/H816_K1_2.jpg' \/><\/center> G\u1ecdi $MD$ l\u00e0 ph\u00e2n gi\u00e1c g\u00f3c $M$ ($D\\in PQ$) <br\/> Suy ra $\\widehat{QMD} = 45^o$ <br\/> Do \u0111\u00f3 $\\Delta MDQ$ vu\u00f4ng c\u00e2n t\u1ea1i $Q$.<br\/> $\\Rightarrow MQ=DQ=5\\, (cm)$ <br\/> M\u00e0 $PQ=PD+DQ=15+5=20\\, (cm)$ <br\/> V\u1eady n\u1eeda chu vi c\u1ee7a h\u00ecnh ch\u1eef nh\u1eadt $MNPQ$ l\u00e0: <br\/> $MQ+PQ=5+20=25\\, (cm)$ <br\/> <span class='basic_pink'> V\u1eady c\u1ea7n \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u00e0 $25$. <\/span> <\/span> "}]}],"id_ques":1452},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[4]],"list":[{"point":10,"ques":" <span class='basic_left'> Cho h\u00ecnh ch\u1eef nh\u1eadt $ABCD$, c\u00f3 $CD$ c\u1ed1 \u0111\u1ecbnh v\u00e0 $M$ l\u00e0 trung \u0111i\u1ec3m c\u1ee7a $AB$. Khi h\u00ecnh ch\u1eef nh\u1eadt thay \u0111\u1ed5i th\u00ec $M$ ch\u1ea1y tr\u00ean \u0111\u01b0\u1eddng n\u00e0o? <\/span>","select":["A. \u0110\u01b0\u1eddng tr\u00f2n $(A;AM)$","B. \u0110\u01b0\u1eddng th\u1eb3ng song song v\u1edbi $CD$","C. \u0110\u01b0\u1eddng tr\u00f2n $(B; BM)$","D. \u0110\u01b0\u1eddng trung tr\u1ef1c c\u1ee7a $CD$"],"explain":" <span class='basic_left'> <center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/hinhhoc/bai6/lv3/img\/H816_K1_3.jpg' \/><\/center> $M$ l\u00e0 trung \u0111i\u1ec3m c\u1ee7a $AB$ suy ra $M$ thu\u1ed9c trung tr\u1ef1c c\u1ee7a $CD$. <br\/> $\\Rightarrow MD=CM$ (t\u00ednh ch\u1ea5t) <br\/> Khi h\u00ecnh ch\u1eef nh\u1eadt thay \u0111\u1ed5i, $CD$ c\u1ed1 \u0111\u1ecbnh. <br\/> Gi\u1ea3 s\u1eed c\u00f3 h\u00ecnh ch\u1eef nh\u1eadt $A'B'CD$ v\u00e0 \u0111i\u1ec3m $M'$ th\u1ecfa m\u00e3n $A'M'=M'B'$ <br\/> Suy ra $M'$ thu\u1ed9c trung tr\u1ef1c c\u1ee7a $CD$. <br\/> $\\Rightarrow DM'=CM'$ (t\u00ednh ch\u1ea5t) <br\/> V\u1eady $M$ s\u1ebd lu\u00f4n n\u1eb1m tr\u00ean \u0111\u01b0\u1eddng trung tr\u1ef1c c\u1ee7a $CD$. <br\/> <span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n l\u00e0 D. <\/span><\/span> ","column":2}]}],"id_ques":1453},{"time":24,"part":[{"title":"\u0110i\u1ec1n k\u1ebft qu\u1ea3 v\u00e0o \u00f4 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank","correct":[[["115"]]],"list":[{"point":10,"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/lv3/img\/H816_K1_4.jpg' \/><\/center> Bi\u1ebft $\\widehat{A}=90^o$; $AM=7\\, cm; AC=9\\, cm$ <br\/> <br\/> T\u00ednh \u0111\u1ed9 d\u00e0i c\u1ea1nh $AB$. <br\/> <br\/><b> Em h\u00e3y \u0111i\u1ec1n: <\/b> $AB=\\sqrt{\\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{}}\\, (cm)$ <\/span> ","hint":" T\u00ednh $BC$ d\u1ef1a v\u00e0o $AM$.","explain":" <span class='basic_left'> <center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/hinhhoc/bai6/lv3/img\/H816_K1_4.jpg' \/><\/center> Do $\\Delta ABC$ vu\u00f4ng t\u1ea1i $A$, m\u00e0 $BM=CM$ n\u00ean $AM=BM=CM=\\dfrac{1}{2}BC$ <br\/> $BC=2AM=14\\, (cm)$ <br\/> \u00c1p d\u1ee5ng \u0111\u1ecbnh l\u00ed Py - ta - go v\u00e0o tam gi\u00e1c vu\u00f4ng $ABC$, ta \u0111\u01b0\u1ee3c: <br\/> $BC^2=AB^2+AC^2$ <br\/> $\\Rightarrow AB^2=BC^2-AC^2=14^2-9^2$ <br\/> $\\Rightarrow AB^2=115$ <br\/> $AB=\\sqrt{115}\\, (cm)$ <br\/> <span class='basic_pink'> V\u1eady c\u1ea7n \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u00e0 $115$. <\/span> <\/span> "}]}],"id_ques":1454},{"time":24,"part":[{"title":"\u0110i\u1ec1n k\u1ebft qu\u1ea3 v\u00e0o \u00f4 tr\u1ed1ng","title_trans":"\u0110\u1ec1 chung cho ba c\u00e2u","temp":"fill_the_blank","correct":[[["5"]]],"list":[{"point":10,"width":20,"type_input":"","ques":"<span class='basic_left'> Cho $\\Delta ABC$ vu\u00f4ng t\u1ea1i $A$, bi\u1ebft $AB=6\\, cm; AC=8\\, cm$. \u0110i\u1ec3m $D$ l\u00e0 trung \u0111i\u1ec3m c\u1ee7a $BC$. K\u1ebb $DH\\bot AB$ t\u1ea1i $H$; $DK\\bot AC$ t\u1ea1i $K$. <br\/> <b> C\u00e2u 1:<\/b> T\u00ednh \u0111\u1ed9 d\u00e0i $AD$. <br\/><br\/> <b> \u0110\u00e1p \u00e1n: <\/b> $AD\\,= \\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{}\\, (cm)$ <\/span> ","explain":" <span class='basic_left'> <center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/hinhhoc/bai6/lv3/img\/H816_K1_5.jpg' \/><\/center> Do $\\Delta ABC$ vu\u00f4ng t\u1ea1i $A$, \u00e1p d\u1ee5ng \u0111\u1ecbnh l\u00fd Py - ta - go, ta \u0111\u01b0\u1ee3c: <br\/> $\\begin{align*}BC^2&=AB^2+AC^2\\\\&=6^2+8^2\\\\&=100 \\end{align*}$ <br\/> $\\Rightarrow BC=10\\, (cm)$ <br\/>L\u1ea1i c\u00f3: $\\Delta ABC$ vu\u00f4ng t\u1ea1i $A$ (gi\u1ea3 thi\u1ebft)<br\/> $D$ l\u00e0 trung \u0111i\u1ec3m c\u1ee7a $BC$ (gi\u1ea3 thi\u1ebft) <br\/> $\\Rightarrow AD=\\dfrac{1}{2}BC=5\\, (cm)$ <br\/> <span class='basic_pink'> V\u1eady c\u1ea7n \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u00e0 $5$. <\/span> <\/span> "}]}],"id_ques":1455},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"\u0110\u1ec1 chung cho ba c\u00e2u","temp":"multiple_choice","correct":[[1]],"list":[{"point":10,"ques":" <span class='basic_left'> Cho $\\Delta ABC$ vu\u00f4ng t\u1ea1i $A$, bi\u1ebft $AB=6\\, cm; AC=8\\, cm$. \u0110i\u1ec3m $D$ l\u00e0 trung \u0111i\u1ec3m c\u1ee7a $BC$. K\u1ebb $DH\\bot AB$ t\u1ea1i $H$; $DK\\bot AC$ t\u1ea1i $K$. <br\/> <b> C\u00e2u 2:<\/b> $AHDK$ l\u00e0 h\u00ecnh g\u00ec? <\/span>","select":["A. H\u00ecnh ch\u1eef nh\u1eadt","B. H\u00ecnh b\u00ecnh h\u00e0nh","C. H\u00ecnh thang"],"explain":" <span class='basic_left'> <center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/hinhhoc/bai6/lv3/img\/H816_K1_5.jpg' \/><\/center> Theo gi\u1ea3 thi\u1ebft: $DH\\bot AB \\Rightarrow \\widehat{DHA}=90^o$ <br\/> $DK\\bot AC \\Rightarrow \\widehat{DKA}=90^o$ <br\/> M\u00e0 $\\widehat{A}=90^o$ (gi\u1ea3 thi\u1ebft) <br\/> $\\Rightarrow$ T\u1ee9 gi\u00e1c $AHDK$ 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":1456},{"time":24,"part":[{"title":"\u0110i\u1ec1n k\u1ebft qu\u1ea3 v\u00e0o \u00f4 tr\u1ed1ng","title_trans":"\u0110\u1ec1 chung cho ba c\u00e2u","temp":"fill_the_blank","correct":[[["12"]]],"list":[{"point":10,"width":20,"type_input":"","ques":"<span class='basic_left'> Cho $\\Delta ABC$ vu\u00f4ng t\u1ea1i $A$, bi\u1ebft $AB=6\\, cm; AC=8\\, cm$. \u0110i\u1ec3m $D$ l\u00e0 trung \u0111i\u1ec3m c\u1ee7a $BC$. K\u1ebb $DH\\bot AB$ t\u1ea1i $H$; $DK\\bot AC$ t\u1ea1i $K$. <br\/> <b> C\u00e2u 3:<\/b> T\u00ednh di\u1ec7n t\u00edch c\u1ee7a t\u1ee9 gi\u00e1c $AHDK$. <br\/><br\/> <b> \u0110\u00e1p \u00e1n: <\/b> $S_{AHDK}\\,= \\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{}\\, (cm^2)$ <\/span> ","hint":"$S_{AHDK}=DH.DK$ <br\/>T\u00ednh $HD$ qua $AC$, t\u00ednh $DK$ qua $AB$.","explain":" <span class='basic_left'> <center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/hinhhoc/bai6/lv3/img\/H816_K1_5.jpg' \/><\/center> $AHDK$ l\u00e0 h\u00ecnh ch\u1eef nh\u1eadt (c\u00e2u 1) <br\/> $\\Rightarrow HD\/\/AK, DK\/\/AH$ hay $HD\/\/AC, DK\/\/AB$.<br\/> X\u00e9t tam gi\u00e1c $ABC$ c\u00f3: $HD\/\/AC, DB=DC$ n\u00ean $HB=HA$. <br\/> $\\Rightarrow DH$ l\u00e0 \u0111\u01b0\u1eddng trung b\u00ecnh c\u1ee7a $\\Delta ABC$. <br\/> $\\Rightarrow HD=\\dfrac{AC}{2}=4\\, (cm)$ <br\/> Ch\u1ee9ng minh t\u01b0\u01a1ng t\u1ef1: $DK=\\dfrac{AB}{2}=3\\, (cm)$ <br\/> Di\u1ec7n t\u00edch h\u00ecnh ch\u1eef nh\u1eadt $AHDK$ l\u00e0: $S_{AHDK}=DH.DK=4.3=12\\, (cm^2)$ <br\/> <span class='basic_pink'> V\u1eady c\u1ea7n \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u00e0 $12$. <\/span> <\/span> "}]}],"id_ques":1457},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"\u0110\u1ec1 chung cho ba c\u00e2u","temp":"multiple_choice","correct":[[1]],"list":[{"point":10,"ques":" <span class='basic_left'> Cho h\u00ecnh thang $MNPQ$ c\u00f3 $\\widehat{M}=\\widehat{Q}=90^o$; $MN=16\\, cm; NP=17\\, cm$ ; $PQ=24\\, cm$. K\u1ebb $NE\\bot PQ$ t\u1ea1i $E$. <br\/> <b> C\u00e2u 1:<\/b> $MNEQ$ l\u00e0 h\u00ecnh g\u00ec? <\/span>","select":["A. H\u00ecnh ch\u1eef nh\u1eadt","B. H\u00ecnh b\u00ecnh h\u00e0nh","C. H\u00ecnh thang"],"explain":" <span class='basic_left'> <center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/hinhhoc/bai6/lv3/img\/H816_K1_6.jpg' \/><\/center> Theo gi\u1ea3 thi\u1ebft: $ME\\bot PQ \\Rightarrow \\widehat{NEQ}=90^o$ <br\/> M\u00e0 $\\widehat{M}=\\widehat{Q}=90^o$ (gi\u1ea3 thi\u1ebft) <br\/> $\\Rightarrow$ T\u1ee9 gi\u00e1c $MNEQ$ 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":1458},{"time":24,"part":[{"title":"\u0110i\u1ec1n k\u1ebft qu\u1ea3 v\u00e0o \u00f4 tr\u1ed1ng","title_trans":"\u0110\u1ec1 chung cho ba c\u00e2u","temp":"fill_the_blank","correct":[[["16"],["8"]]],"list":[{"point":10,"width":20,"type_input":"","ques":"<span class='basic_left'> Cho h\u00ecnh thang $MNPQ$ c\u00f3 $\\widehat{M}=\\widehat{Q}=90^o$; $MN=16\\, cm; NP=17\\, cm$ ; $PQ=24\\, cm$. K\u1ebb $NE\\bot PQ$ t\u1ea1i $E$. <br\/> <b> C\u00e2u 2:<\/b> T\u00ednh $EQ$ v\u00e0 $EP$. <br\/><br\/> <b> \u0110\u00e1p \u00e1n: <\/b> <br\/> $EQ\\,= \\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{}\\, (cm)$ <br\/> $EP\\,= \\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{}\\, (cm)$ <\/span> ","explain":" <span class='basic_left'> <center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/hinhhoc/bai6/lv3/img\/H816_K1_6.jpg' \/><\/center> Theo c\u00e2u 1 tr\u00ean, ta ch\u1ee9ng minh \u0111\u01b0\u1ee3c $MNEQ$ l\u00e0 h\u00ecnh ch\u1eef nh\u1eadt. <br\/> $\\Rightarrow EQ=MN=16\\, (cm)$ <br\/> Do $PQ=EQ+EP\\Rightarrow EP=PQ-EQ=24-16=8\\, (cm)$ <br\/> <span class='basic_pink'> V\u1eady c\u1ea7n \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u00e0 $16$ v\u00e0 $8$. <\/span> <\/span> "}]}],"id_ques":1459},{"time":24,"part":[{"title":"\u0110i\u1ec1n k\u1ebft qu\u1ea3 v\u00e0o \u00f4 tr\u1ed1ng","title_trans":"\u0110\u1ec1 chung cho ba c\u00e2u","temp":"fill_the_blank","correct":[[["240"],["300"]]],"list":[{"point":10,"width":20,"type_input":"","ques":"<span class='basic_left'> Cho h\u00ecnh thang $MNPQ$ c\u00f3 $\\widehat{M}=\\widehat{Q}=90^o$; $MN=16\\, cm; NP=17\\, cm$ ; $PQ=24\\, cm$. K\u1ebb $NE\\bot PQ=E$ <br\/> <b> C\u00e2u 3:<\/b> T\u00ednh di\u1ec7n t\u00edch c\u00e1c t\u1ee9 gi\u00e1c $MNEQ$ v\u00e0 $MNPQ$. <br\/><br\/> <b> \u0110\u00e1p \u00e1n: <\/b> <br\/> $S_{MNEQ}\\,= \\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{}\\, (cm^2)$ <br\/> $S_{MNPQ}\\,= \\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{}\\, (cm^2)$ <\/span> ","hint":"$S_{MNEQ}=MN.NE$ v\u00e0 $S_{MNPQ}=S_{MNEQ}+S_{NEP}$","explain":" <span class='basic_left'> <center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/hinhhoc/bai6/lv3/img\/H816_K1_6.jpg' \/><\/center> Theo c\u00e2u 1 tr\u00ean, ta ch\u1ee9ng minh \u0111\u01b0\u1ee3c $MNEQ$ l\u00e0 h\u00ecnh ch\u1eef nh\u1eadt. <br\/> $\\Rightarrow S_{MNEQ}=MN.NE$ <br\/> X\u00e9t tam gi\u00e1c vu\u00f4ng $NEP$: <br\/> $NP^2=NE^2+EP^2$ (\u0111\u1ecbnh l\u00fd Pi - ta - go) <br\/> $\\Rightarrow NE^2=NP^2-EP^2=17^2-8^2=225$ <br\/> $\\Rightarrow NE=15\\, (cm)$ <br\/> Do \u0111\u00f3: $S_{MNEQ}=MN.NE$$=16.15=240\\, (cm^2)$ <br\/> $S_{MNPQ}=S_{MNEQ}+S_{NEP}$ <br\/> $=240+\\dfrac{1}{2}NE.EP$ <br\/> $=240+\\dfrac{1}{2}.15.8=300\\, (cm^2)$ <br\/> <span class='basic_pink'> V\u1eady c\u1ea7n \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u1ea7n l\u01b0\u1ee3t t\u1eeb tr\u00ean xu\u1ed1ng d\u01b0\u1edbi l\u00e0 $240$; $300$. <\/span> <\/span> "}]}],"id_ques":1460}],"lesson":{"save":0,"level":3}}

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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)

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