{"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}}