{"segment":[{"time":24,"part":[{"title":"\u0110i\u1ec1n \u0111\u00e1p \u00e1n th\u00edch h\u1ee3p v\u00e0o c\u00e1c \u00f4 tr\u1ed1ng","title_trans":"M\u1ed7i \u00f4 tr\u1ed1ng ch\u1ec9 \u0111i\u1ec1n m\u1ed9t \u0111\u00e1p \u00e1n","temp":"fill_the_blank","correct":[[["OO'","O'O"],["AB","BA","CD","DC"],["h","OO'","O'O","AB","BA","CD","DC"],["R","OA","O'B"]]],"list":[{"point":5,"width":60,"type_input":"","ques":"<span class='basic_left'>Cho h\u00ecnh v\u1ebd sau:<br\/><center><img src='https://www.luyenthi123.com/file/luyenthi123/lop9/toan/hinhhoc/bai22/lv1/img\/H941_D1.png' \/><\/center><br\/>Tr\u1ee5c c\u1ee7a h\u00ecnh tr\u1ee5 l\u00e0 _input_; <br\/>\u0110\u01b0\u1eddng sinh c\u1ee7a h\u00ecnh tr\u1ee5 l\u00e0: _input_<br\/>Chi\u1ec1u cao c\u1ee7a h\u00ecnh tr\u1ee5 l\u00e0 _input_<br\/>B\u00e1n k\u00ednh \u0111\u00e1y l\u00e0 _input_","hint":"","explain":"<span class='basic_left'><center><img src='https://www.luyenthi123.com/file/luyenthi123/lop9/toan/hinhhoc/bai22/lv1/img\/H941_D1.png' \/><\/center><br\/>Khi quay h\u00ecnh ch\u1eef nh\u1eadt $OO'BA$ m\u1ed9t v\u00f2ng quanh c\u1ea1nh $OO\u2019 $ c\u1ed1 \u0111\u1ecbnh, ta \u0111\u01b0\u1ee3c m\u1ed9t h\u00ecnh tr\u1ee5. Khi \u0111\u00f3: <br\/>- Tr\u1ee5c c\u1ee7a h\u00ecnh tr\u1ee5 l\u00e0: $OO\u2019$<br\/>- C\u1ea1nh $AB$ qu\u00e9t n\u00ean m\u1eb7t xung quanh c\u1ee7a h\u00ecnh tr\u1ee5, m\u1ed7i v\u1ecb tr\u00ed c\u1ee7a $AB$ \u0111\u01b0\u1ee3c g\u1ecdi l\u00e0 \u0111\u01b0\u1eddng sinh. \u0110\u01b0\u1eddng sinh c\u1ee7a h\u00ecnh tr\u1ee5 l\u00e0: $AB,$ $CD$<br\/>- C\u00e1c \u0111\u01b0\u1eddng sinh c\u1ee7a h\u00ecnh tr\u1ee5 vu\u00f4ng g\u00f3c v\u1edbi m\u1eb7t ph\u1eb3ng \u0111\u00e1y n\u00ean \u0111\u1ed9 d\u00e0i \u0111\u01b0\u1eddng sinh l\u00e0 chi\u1ec1u cao c\u1ee7a h\u00ecnh tr\u1ee5. Do \u0111\u00f3 chi\u1ec1u cao c\u1ee7a h\u00ecnh tr\u1ee5 l\u00e0 $h$<br\/>B\u00e1n k\u00ednh \u0111\u00e1y: $OA=O'B=R$<br\/><span class='basic_pink'>V\u1eady c\u00e1c \u0111\u00e1p \u00e1n c\u1ea7n \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u1ea7n l\u01b0\u1ee3t l\u00e0 $OO';$ $AB;$ $h;$ $R.$<\/span><\/span>"}]}],"id_ques":1661},{"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'>Cho h\u00ecnh tr\u1ee5 c\u00f3 b\u00e1n k\u00ednh \u0111\u00e1y l\u00e0 $R$ v\u00e0 chi\u1ec1u cao $h.$ Di\u1ec7n t\u00edch xung quanh c\u1ee7a h\u00ecnh tr\u1ee5 l\u00e0: ","select":["A. ${{S}_{xq}}=\\pi Rh$ ","B. ${{S}_{xq}}=2\\pi Rh$ ","C. ${{S}_{xq}}=4\\pi Rh$ "],"hint":"","explain":"<span class='basic_left'><center><img src='https://www.luyenthi123.com/file/luyenthi123/lop9/toan/hinhhoc/bai22/lv1/img\/H941_D1.png' \/><\/center><br\/>Di\u1ec7n t\u00edch xung quanh c\u1ee7a h\u00ecnh tr\u1ee5 l\u00e0 ${{S}_{xq}}=2\\pi Rh$<br\/>Trong \u0111\u00f3:<br\/>$R:$ B\u00e1n k\u00ednh \u0111\u00e1y<br\/>$h:$ Chi\u1ec1u cao \u0111\u00e1y<br\/><span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 B.<\/span> <\/span>","column":3}]}],"id_ques":1662},{"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 tr\u1ee5 c\u00f3 b\u00e1n k\u00ednh \u0111\u00e1y l\u00e0 $r$ v\u00e0 chi\u1ec1u cao $h.$ Di\u1ec7n t\u00edch to\u00e0n ph\u1ea7n c\u1ee7a h\u00ecnh tr\u1ee5 l\u00e0: ","select":["A. ${{S}_{tp}}=2\\pi rh+\\pi {{r}^{2}}$ ","B. ${{S}_{tp}}=\\pi rh+2\\pi {{r}^{2}}$ ","C. ${{S}_{tp}}=2\\pi rh+2\\pi {{r}^{2}}$ "],"hint":"","explain":"<span class='basic_left'><center><img src='https://www.luyenthi123.com/file/luyenthi123/lop9/toan/hinhhoc/bai22/lv1/img\/H941_D2.png' \/><\/center><br\/>Di\u1ec7n t\u00edch to\u00e0n ph\u1ea7n c\u1ee7a h\u00ecnh tr\u1ee5 b\u1eb1ng di\u1ec7n t\u00edch xung quanh h\u00ecnh tr\u1ee5 c\u1ed9ng v\u1edbi di\u1ec7n t\u00edch hai \u0111\u00e1y:<br\/>${{S}_{tp}}=2\\pi rh+2\\pi {{r}^{2}}$<br\/>Trong \u0111\u00f3:<br\/>$r:$ B\u00e1n k\u00ednh \u0111\u00e1y<br\/>$h:$ Chi\u1ec1u cao \u0111\u00e1y<br\/><span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 C.<\/span> <\/span>","column":3}]}],"id_ques":1663},{"time":24,"part":[{"title":"\u0110i\u1ec1n s\u1ed1 th\u00edch h\u1ee3p v\u00e0o \u00f4 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank","correct":[[["70"]]],"list":[{"point":5,"width":60,"type_input":"","ques":"<span class='basic_left'>T\u00ednh di\u1ec7n t\u00edch xung quanh c\u1ee7a m\u1ed9t h\u00ecnh tr\u1ee5 c\u00f3 b\u00e1n k\u00ednh \u0111\u00e1y l\u00e0 $5$ $cm$ v\u00e0 chi\u1ec1u cao l\u00e0 $7$ $cm.$ <br\/><b> \u0110\u00e1p s\u1ed1: <\/b> $S_{xq}=$ _input_ $\\pi$$(cm^2)$ ","hint":"","explain":"<span class='basic_left'>Di\u1ec7n t\u00edch xung quanh c\u1ee7a h\u00ecnh tr\u1ee5 l\u00e0: <br\/>${{S}_{xq}}=2\\pi Rh=2\\pi .5.7=70\\pi \\left( c{{m}^{2}} \\right)$<br\/><span class='basic_pink'>V\u1eady s\u1ed1 c\u1ea7n \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u00e0 $70.$<\/span><\/span>"}]}],"id_ques":1664},{"time":24,"part":[{"title":"\u0110i\u1ec1n s\u1ed1 th\u00edch h\u1ee3p v\u00e0o \u00f4 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank","correct":[[["39"]]],"list":[{"point":5,"width":60,"type_input":"","ques":"<span class='basic_left'>Di\u1ec7n t\u00edch xung quanh c\u1ee7a m\u1ed9t h\u00ecnh tr\u1ee5 c\u00f3 chu vi \u0111\u01b0\u1eddng tr\u00f2n \u0111\u00e1y l\u00e0 $13$ $cm$ v\u00e0 chi\u1ec1u cao l\u00e0 $3$ $cm$ l\u00e0 _input_$(cm^2)$ ","hint":"","explain":"<span class='basic_left'>V\u00ec chu vi \u0111\u01b0\u1eddng tr\u00f2n \u0111\u00e1y l\u00e0 $13$ $cm$ n\u00ean ta c\u00f3: $2\\pi R=13$ $(cm)$<br\/>Di\u1ec7n t\u00edch xung quanh c\u1ee7a h\u00ecnh tr\u1ee5 l\u00e0:<br\/> ${{S}_{xq}}=2\\pi Rh=\\left( 2\\pi R \\right).h=13.3=39\\left( c{{m}^{2}} \\right)$<br\/><span class='basic_pink'>V\u1eady s\u1ed1 c\u1ea7n \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u00e0 $39$<\/span><\/span>"}]}],"id_ques":1665},{"time":24,"part":[{"title":"\u0110i\u1ec1n s\u1ed1 th\u00edch h\u1ee3p v\u00e0o \u00f4 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank","correct":[[["7,96"]]],"list":[{"point":5,"width":60,"type_input":"","ques":"<span class='basic_left'>M\u1ed9t h\u00ecnh tr\u1ee5 c\u00f3 b\u00e1n k\u00ednh \u0111\u00e1y b\u1eb1ng $6$ $cm$ v\u00e0 di\u1ec7n t\u00edch xung quanh b\u1eb1ng $300$ $cm^2.$ Chi\u1ec1u cao c\u1ee7a h\u00ecnh tr\u1ee5 l\u00e0: _input_$(cm)$ (l\u00e0m tr\u00f2n \u0111\u1ebfn s\u1ed1 th\u1eadp ph\u00e2n th\u1ee9 hai)<\/span>","hint":"","explain":"<span class='basic_left'>Di\u1ec7n t\u00edch xung quanh c\u1ee7a h\u00ecnh tr\u1ee5 l\u00e0 $300$ $cm^2$ n\u00ean ta c\u00f3:<br\/>$2\\pi Rh=300\\Leftrightarrow h=\\dfrac{300}{2\\pi R}=\\dfrac{300}{2\\pi .6}=\\dfrac{25}{\\pi }\\approx 7,96$$(cm)$<br\/><span class='basic_pink'>V\u1eady s\u1ed1 c\u1ea7n \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u00e0 $7,96.$<\/span><\/span>"}]}],"id_ques":1666},{"time":24,"part":[{"title":"\u0110i\u1ec1n s\u1ed1 th\u00edch h\u1ee3p v\u00e0o \u00f4 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank","correct":[[["3"]]],"list":[{"point":5,"width":60,"type_input":"","ques":"<span class='basic_left'>M\u1ed9t h\u00ecnh tr\u1ee5 c\u00f3 b\u00e1n k\u00ednh l\u00e0 $3$ $cm.$ Bi\u1ebft di\u1ec7n t\u00edch to\u00e0n ph\u1ea7n g\u1ea5p \u0111\u00f4i di\u1ec7n t\u00edch xung quanh. T\u00ednh chi\u1ec1u cao h\u00ecnh tr\u1ee5.<br\/><b>\u0110\u00e1p s\u1ed1:<\/b> _input_$(cm)$<\/span>","hint":"T\u1eeb ${{S}_{tp}}=2{{S}_{xq}}$, ta thay c\u00e1c c\u00f4ng th\u1ee9c t\u00ednh v\u00e0o r\u1ed3i t\u00ecm $h$","explain":"<span class='basic_left'>Ta c\u00f3:<br\/>$\\begin{align} & \\,\\,\\,\\,\\,\\,{{S}_{tp}}=2{{S}_{xq}} \\\\ & \\Leftrightarrow 2\\pi Rh+2\\pi {{R}^{2}}=2.2\\pi Rh \\\\ & \\Leftrightarrow 2\\pi R\\left( h+R \\right)=4\\pi Rh\\,\\,\\,\\,\\,\\,\\,\\,\\left( \\text{do}\\,\\pi R\\ne 0 \\right) \\\\ & \\Leftrightarrow h+R=2h \\\\ & \\Leftrightarrow h=R=3\\left( cm \\right) \\\\ \\end{align}$<br\/>V\u1eady chi\u1ec1u cao c\u1ee7a h\u00ecnh tr\u1ee5 l\u00e0 $3$ $cm.$<br\/><span class='basic_pink'>V\u1eady s\u1ed1 c\u1ea7n \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u00e0 $3.$<\/span><\/span>"}]}],"id_ques":1667},{"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'>Cho h\u00ecnh tr\u1ee5 c\u00f3 b\u00e1n k\u00ednh \u0111\u00e1y l\u00e0 $R$ v\u00e0 chi\u1ec1u cao $h.$ Th\u1ec3 t\u00edch h\u00ecnh tr\u1ee5 l\u00e0: ","select":["A. $V=2\\pi {{R}^{2}}h$","B. $V=\\pi {{R}^{2}}h$","C. $V=\\pi R{{h}^{2}}$"],"hint":"","explain":"<span class='basic_left'><center><img src='https://www.luyenthi123.com/file/luyenthi123/lop9/toan/hinhhoc/bai22/lv1/img\/H941_D1.png' \/><\/center><br\/>Th\u1ec3 t\u00edch h\u00ecnh tr\u1ee5 l\u00e0: $V=S_\u0111.h=\\pi {{R}^{2}}h$ Trong \u0111\u00f3:<br\/>$R:$ B\u00e1n k\u00ednh \u0111\u00e1y<br\/>$h:$ Chi\u1ec1u cao \u0111\u00e1y<br\/>$S_{\u0111}$ l\u00e0 di\u1ec7n t\u00edch \u0111\u00e1y<br\/><span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 B.<\/span> <\/span>","column":3}]}],"id_ques":1668},{"time":24,"part":[{"title":"\u0110i\u1ec1n s\u1ed1 th\u00edch h\u1ee3p v\u00e0o \u00f4 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank","correct":[[["200"]]],"list":[{"point":5,"width":60,"type_input":"","ques":"<span class='basic_left'>T\u00ednh th\u1ec3 t\u00edch h\u00ecnh tr\u1ee5 c\u00f3 b\u00e1n k\u00ednh h\u00ecnh tr\u00f2n \u0111\u00e1y l\u00e0 $5$ $mm,$ chi\u1ec1u cao l\u00e0 $8$ $mm.$<br\/><b>\u0110\u00e1p s\u1ed1: <\/b> _input_$\\pi$$(mm^3)$ <\/span>","hint":"","explain":"<span class='basic_left'>Th\u1ec3 t\u00edch h\u00ecnh tr\u1ee5 l\u00e0:<br\/>$V=\\pi {{R}^{2}}h=\\pi {{.5}^{2}}.8=200\\pi \\left( m{{m}^{3}} \\right)$ <br\/><span class='basic_pink'>V\u1eady s\u1ed1 c\u1ea7n \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u00e0 $200.$<\/span><\/span>"}]}],"id_ques":1669},{"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":[[4]],"list":[{"point":5,"ques":"<span class='basic_left'>M\u1ed9t h\u00ecnh tr\u1ee5 c\u00f3 \u0111\u01b0\u1eddng cao b\u1eb1ng \u0111\u01b0\u1eddng k\u00ednh \u0111\u00e1y. Bi\u1ebft th\u1ec3 t\u00edch c\u1ee7a n\u00f3 l\u00e0 $128\\pi $ $(cm^3)$<br\/><b>C\u00e2u a:<\/b> T\u00ednh b\u00e1n k\u00ednh \u0111\u00e1y. ","select":["A. $R=2\\sqrt[3]{2}$ $(cm)$","B. $R=4\\sqrt[3]{2}$ $(cm)$","C. $R=4\\sqrt{2}$ $(cm)$","D. $R=4$ $(cm)$"],"hint":"\u00c1p d\u1ee5ng c\u00f4ng th\u1ee9c t\u00ednh th\u1ec3 t\u00edch, ta gi\u1ea3i ph\u01b0\u01a1ng tr\u00ecnh $V=128\\pi$ \u0111\u1ec3 t\u00ecm $R$","explain":"<span class='basic_left'>\u00c1p d\u1ee5ng c\u00f4ng th\u1ee9c $V=\\pi {{R}^{2}}h$ <br\/>Do \u0111\u01b0\u1eddng cao b\u1eb1ng \u0111\u01b0\u1eddng k\u00ednh \u0111\u00e1y n\u00ean $h=2R$<br\/>Suy ra $V=2\\pi {{R}^{3}}$ <br\/>Do $V=128\\pi $ n\u00ean $2\\pi {{R}^{3}}=128\\pi \\Leftrightarrow {{R}^{3}}=64\\Leftrightarrow R=4$ $(cm)$<br\/><span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 D.<\/span> <\/span>","column":2}]}],"id_ques":1670},{"time":24,"part":[{"title":"\u0110i\u1ec1n s\u1ed1 th\u00edch h\u1ee3p v\u00e0o ch\u1ed7 tr\u1ed1ng","title_trans":"\u0110\u1ec1 chung cho hai c\u00e2u","temp":"fill_the_blank","correct":[[["64"],["80"]]],"list":[{"point":5,"width":40,"content":"","type_input":"","ques":"<span class='basic_left'>M\u1ed9t h\u00ecnh tr\u1ee5 c\u00f3 \u0111\u01b0\u1eddng cao b\u1eb1ng \u0111\u01b0\u1eddng k\u00ednh \u0111\u00e1y. Bi\u1ebft th\u1ec3 t\u00edch c\u1ee7a n\u00f3 l\u00e0 $128\\pi $ $(cm^3)$<br\/><b>C\u00e2u b:<\/b> T\u00ednh di\u1ec7n t\u00edch xung quanh v\u00e0 di\u1ec7n t\u00edch to\u00e0n ph\u1ea7n c\u1ee7a h\u00ecnh tr\u1ee5.<br\/><b> \u0110\u00e1p s\u1ed1: <\/b> $S_{xq}= $ _input_ $\\pi$ $(cm^2)$ v\u00e0 $S_{tp}= $_input_$\\pi$ $(cm^2)$ <br\/><\/span>","hint":"","explain":"<span class='basic_left'>Theo k\u1ebft qu\u1ea3 <b>c\u00e2u a<\/b>, ta c\u00f3 b\u00e1n k\u00ednh \u0111\u00e1y c\u1ee7a h\u00ecnh tr\u1ee5 l\u00e0: $R=4$ $(cm)$<br\/>Di\u1ec7n t\u00edch xung quanh c\u1ee7a h\u00ecnh tr\u1ee5 l\u00e0:<br\/> ${{S}_{xq}}=2\\pi Rh=2\\pi R.\\left( 2R \\right)=4\\pi {{R}^{2}}=4\\pi.4^{2}=64\\pi \\left( c{{m}^{2}} \\right)$<br\/>Di\u1ec7n t\u00edch to\u00e0n ph\u1ea7n c\u1ee7a h\u00ecnh tr\u1ee5 l\u00e0:<br\/> ${{S}_{tp}}={{S}_{xq}}+\\pi {{R}^{2}}=64\\pi+\\pi.4^2=80 \\pi \\left( c{{m}^{2}} \\right)$ <br\/><span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n c\u1ea7n \u0111i\u1ec1n l\u1ea7n l\u01b0\u1ee3t l\u00e0 $64;$ $80.$ <\/span><\/span>"}]}],"id_ques":1671},{"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":"<span class='basic_left'>Chi\u1ec1u cao c\u1ee7a m\u1ed9t h\u00ecnh tr\u1ee5 b\u1eb1ng b\u00e1n k\u00ednh \u0111\u00e1y. Di\u1ec7n t\u00edch xung quanh c\u1ee7a h\u00ecnh tr\u1ee5 l\u00e0 $50\\pi$ $cm^2. $ H\u00e3y t\u00ednh b\u00e1n k\u00ednh \u0111\u00e1y $R$ v\u00e0 th\u1ec3 t\u00edch $V$ c\u1ee7a h\u00ecnh tr\u1ee5. ","select":["A. $R = 5\\, cm$ v\u00e0 $V =1250\\pi cm^3$","B. $R =5\\sqrt{2}\\, cm$ v\u00e0 $V = 250\\sqrt{2}\\pi \\, cm^3$","C. $R =5\\, cm$ v\u00e0 $V = 250\\sqrt{2}\\pi \\, cm^3$","D. $R =5\\, cm$ v\u00e0 $V = 125\\pi \\, cm^3$"],"hint":"\u00c1p d\u1ee5ng c\u00f4ng th\u1ee9c t\u00ednh di\u1ec7n t\u00edch xung quanh, ta gi\u1ea3i ph\u01b0\u01a1ng tr\u00ecnh $S_{xq}=314$ \u0111\u1ec3 t\u00ecm $R$","explain":"<span class='basic_left'>\u00c1p d\u1ee5ng c\u00f4ng th\u1ee9c: ${{S}_{xq}}=2\\pi Rh$ <br\/>Do $R=h$ v\u00e0 ${{S}_{xq}}=50\\pi$ $cm^2$ n\u00ean ta c\u00f3:<br\/>$\\begin{align} & \\,\\,\\,\\,\\,2\\pi {{R}^{2}}=50\\pi \\\\ & \\Leftrightarrow {{R}^{2}}=25 \\\\ & \\Rightarrow R=5\\left( cm \\right) \\\\ \\end{align}$ <br\/>Th\u1ec3 t\u00edch h\u00ecnh tr\u1ee5 l\u00e0: $V=\\pi {{R}^{2}}h=\\pi {{R}^{3}}=\\pi .5^3=125\\pi \\left( c{{m}^{3}} \\right)$ <br\/><span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 D.<\/span> <\/span>","column":2}]}],"id_ques":1672},{"time":24,"part":[{"title":"\u0110i\u1ec1n k\u1ebft qu\u1ea3 th\u00edch h\u1ee3p v\u00e0o c\u00e1c ch\u1ed7 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank","correct":[[["4"],["32"],["40"],["32"]]],"list":[{"point":5,"width":40,"content":"","type_input":"","ques":"<span class='basic_left'><table><tr><td>H\u00ecnh v\u1ebd<\/td><td>B\u00e1n k\u00ednh \u0111\u00e1y <br\/>$(cm)$<\/td><td>Chi\u1ec1u cao<br\/>$(cm)$<\/td><td>Di\u1ec7n t\u00edch \u0111\u00e1y <br\/>$(cm^2)$<\/td><td>Di\u1ec7n t\u00edch xung quanh<br\/>$(cm^2)$<\/td><td>Di\u1ec7n t\u00edch to\u00e0n ph\u1ea7n<br\/>$(cm^2)$<\/td><td>Th\u1ec3 t\u00edch<br\/>$(cm^3)$<\/td><\/tr><tr><td><img src='https://www.luyenthi123.com/file/luyenthi123/lop9/toan/hinhhoc/bai22/lv1/img\/H941_D3.png' \/><\/td><td>$2$<\/td><td>$8$<\/td><td>_input_$\\pi$<\/td><td>_input_$\\pi$<\/td><td>_input_$\\pi$<\/td><td>_input_$\\pi$<\/td><\/tr><\/table><\/span>","hint":"","explain":"<span class='basic_left'>Di\u1ec7n t\u00edch \u0111\u00e1y: ${{S}_{\u0111}}=\\pi {{R}^{2}}=\\pi {{.2}^{2}}=4\\pi \\left( c{{m}^{2}} \\right)$ <br\/>Di\u1ec7n t\u00edch xung quanh: ${{S}_{xq}}=2\\pi Rh=2\\pi .2.8=32\\pi \\left( c{{m}^{2}} \\right)$ <br\/>Di\u1ec7n t\u00edch to\u00e0n ph\u1ea7n: ${{S}_{xq}}+2{{S}_{\u0111}}=32\\pi+2.4\\pi=40\\pi \\left( c{{m}^{2}} \\right)$ <br\/>Th\u1ec3 t\u00edch: $V=\\pi {{R}^{2}}h=\\pi {{.2}^{2}}.8=32\\pi \\left( c{{m}^{3}} \\right)$ <br\/><span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n c\u1ea7n \u0111i\u1ec1n l\u1ea7n l\u01b0\u1ee3t t\u1eeb tr\u00e1i sang ph\u1ea3i l\u00e0 $4;$$ 32;$$40;$ $32.$ <\/span><\/span>"}]}],"id_ques":1673},{"time":24,"part":[{"title":"\u0110i\u1ec1n k\u1ebft qu\u1ea3 th\u00edch h\u1ee3p v\u00e0o c\u00e1c ch\u1ed7 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank","correct":[[["4"],["16"],["32"],["64"]]],"list":[{"point":5,"width":40,"content":"","type_input":"","ques":"<span class='basic_left'><table><tr><td>H\u00ecnh v\u1ebd<\/td><td>B\u00e1n k\u00ednh \u0111\u00e1y <br\/>$(cm)$<\/td><td>Chi\u1ec1u cao<br\/>$(cm)$<\/td><td>Chu vi \u0111\u00e1y<br\/>$(cm)$<\/td><td>Di\u1ec7n t\u00edch \u0111\u00e1y <br\/>$(cm^2)$<\/td><td>Di\u1ec7n t\u00edch xung quanh<br\/>$(cm^2)$<\/td><td>Th\u1ec3 t\u00edch<br\/>$(cm^3)$<\/td><\/tr><tr><td><img src='https://www.luyenthi123.com/file/luyenthi123/lop9/toan/hinhhoc/bai22/lv1/img\/H941_D3.png' \/><\/td><td>_input_<\/td><td>$4$<\/td><td>$8\\pi $ <\/td><td>_input_$\\pi$<\/td><td>_input_$\\pi$<\/td><td>_input_$\\pi$<\/td><\/tr><\/table><\/span>","hint":"","explain":"<span class='basic_left'>Chu vi \u0111\u00e1y b\u1eb1ng $8\\pi $ $cm$ n\u00ean $2\\pi R=8\\pi \\Rightarrow R=4\\left( cm \\right)$ <br\/>Di\u1ec7n t\u00edch \u0111\u00e1y: ${{S}_{\u0111}}=\\pi {{R}^{2}}=\\pi {{.4}^{2}}=16\\pi \\left( c{{m}^{2}} \\right)$ <br\/>Di\u1ec7n t\u00edch xung quanh: ${{S}_{xq}}=2\\pi Rh=2\\pi .4.4=32\\pi \\left( c{{m}^{2}} \\right)$ <br\/>Th\u1ec3 t\u00edch: $V=\\pi {{R}^{2}}h=\\pi {{.4}^{2}}.4=64\\pi \\left( c{{m}^{3}} \\right)$ <br\/><span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n c\u1ea7n \u0111i\u1ec1n l\u1ea7n l\u01b0\u1ee3t t\u1eeb tr\u00e1i sang ph\u1ea3i l\u00e0 $4;$$16;$$ 32;$ $64.$ <\/span><\/span>"}]}],"id_ques":1674},{"time":24,"part":[{"title":"\u0110i\u1ec1n k\u1ebft qu\u1ea3 th\u00edch h\u1ee3p v\u00e0o c\u00e1c ch\u1ed7 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank","correct":[[["3"],["9"],["18"],["36"]]],"list":[{"point":5,"width":40,"content":"","type_input":"","ques":"<span class='basic_left'><table><tr><td>H\u00ecnh v\u1ebd<\/td><td>B\u00e1n k\u00ednh \u0111\u00e1y <br\/>$(cm)$<\/td><td>Chi\u1ec1u cao<br\/>$(cm)$<\/td><td>Di\u1ec7n t\u00edch \u0111\u00e1y <br\/>$(cm^2)$<\/td><td>Di\u1ec7n t\u00edch xung quanh<br\/>$(cm^2)$<\/td><td>Di\u1ec7n t\u00edch to\u00e0n ph\u1ea7n<br\/>$(cm^2)$<\/td><td>Th\u1ec3 t\u00edch<br\/>$(cm^3)$<\/td><\/tr><tr><td><img src='https://www.luyenthi123.com/file/luyenthi123/lop9/toan/hinhhoc/bai22/lv1/img\/H941_D3.png' \/><\/td><td>$3$<\/td><td>_input_<\/td><td>_input_$\\pi$<\/td><td>_input_$\\pi$<\/td><td>_input_$\\pi$<\/td><td> $27\\pi $<\/td><\/tr><\/table><\/span>","hint":"T\u1eeb c\u00f4ng th\u1ee9c th\u1ec3 t\u00edch, ta gi\u1ea3i ph\u01b0\u01a1ng tr\u00ecnh: $V= 27\\pi $ \u0111\u1ec3 t\u00ecm chi\u1ec1u cao tr\u01b0\u1edbc.","explain":"<span class='basic_left'>Th\u1ec3 t\u00edch b\u1eb1ng $27\\pi $ $cm^3$ n\u00ean<br\/> $\\pi {{R}^{2}}h=27\\pi \\Rightarrow h=\\dfrac{27\\pi }{\\pi {{R}^{2}}}=\\dfrac{27\\pi }{\\pi {{3}^{2}}}=3\\left( cm \\right)$ <br\/>Di\u1ec7n t\u00edch \u0111\u00e1y: ${{S}_{\u0111}}=\\pi {{R}^{2}}=\\pi {{.3}^{2}}=9\\pi \\left( c{{m}^{2}} \\right)$ <br\/>Di\u1ec7n t\u00edch xung quanh: ${{S}_{xq}}=2\\pi Rh=2\\pi .3.3=18\\pi \\left( c{{m}^{2}} \\right)$ <br\/>Di\u1ec7n t\u00edch to\u00e0n ph\u1ea7n: ${{S}_{xq}}+2{{S}_{\u0111}}=18\\pi +2.9\\pi=36 \\pi\\left( c{{m}^{2}} \\right)$ <br\/><span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n c\u1ea7n \u0111i\u1ec1n l\u1ea7n l\u01b0\u1ee3t t\u1eeb tr\u00e1i sang ph\u1ea3i l\u00e0 $3;$$ 9;$$18;$ $36.$ <\/span><\/span>"}]}],"id_ques":1675},{"time":24,"part":[{"title":"\u0110i\u1ec1n s\u1ed1 th\u00edch h\u1ee3p v\u00e0o ch\u1ed7 tr\u1ed1ng","title_trans":"\u0110\u1ec1 chung cho hai c\u00e2u","temp":"fill_the_blank","correct":[[["2"],["5"]]],"list":[{"point":5,"width":40,"content":"","type_input":"","ques":"<span class='basic_left'>M\u1ed9t h\u00ecnh tr\u1ee5 c\u00f3 di\u1ec7n t\u00edch xung quanh l\u00e0 $20\\pi $ $\\left( c{{m}^{2}} \\right)$ v\u00e0 di\u1ec7n t\u00edch to\u00e0n ph\u1ea7n l\u00e0 $28\\pi \\left( c{{m}^{2}} \\right)$.<br\/><b>C\u00e2u a:<\/b> B\u00e1n k\u00ednh \u0111\u00e1y l\u00e0 _input_$(cm)$; chi\u1ec1u cao h\u00ecnh tr\u1ee5 l\u00e0 _input_$(cm)$<\/span>","hint":"T\u1eeb $S_{tp}=S_{xq}+2S_{\u0111\u00e1y},$ ta t\u00ecm $R$","explain":"<span class='basic_left'>Ta c\u00f3: <br\/>$\\begin{align} & {{S}_{tp}}={{S}_{xq}}+2{{S}_{\u0111\u00e1y}} \\\\ & \\Rightarrow {{S}_{\u0111\u00e1y}}=\\dfrac{{{S}_{tp}}-{{S}_{xq}}}{2}=\\dfrac{28\\pi -20\\pi }{2}=4\\pi \\left( c{{m}^{2}} \\right) \\\\ \\end{align}$ <br\/>M\u00e0 ${{S}_{\u0111\u00e1y}}=\\pi {{R}^{2}}\\Rightarrow \\pi {{R}^{2}}=4\\pi \\Leftrightarrow {{R}^{2}}=4\\Leftrightarrow R=2\\left( cm \\right)$<br\/>Ta c\u00f3 ${{S}_{xq}}=2\\pi Rh\\Rightarrow h=\\dfrac{{{S}_{xq}}}{2\\pi R}=\\dfrac{20\\pi }{2\\pi .2}=5\\left( cm \\right)$ <br\/><span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n c\u1ea7n \u0111i\u1ec1n l\u1ea7n l\u01b0\u1ee3t l\u00e0 $2;$$ 5.$ <\/span><\/span>"}]}],"id_ques":1676},{"time":24,"part":[{"title":"\u0110i\u1ec1n s\u1ed1 th\u00edch h\u1ee3p v\u00e0o ch\u1ed7 tr\u1ed1ng","title_trans":"\u0110\u1ec1 chung cho hai c\u00e2u","temp":"fill_the_blank","correct":[[["20"]]],"list":[{"point":5,"width":40,"content":"","type_input":"","ques":"<span class='basic_left'>M\u1ed9t h\u00ecnh tr\u1ee5 c\u00f3 di\u1ec7n t\u00edch xung quanh l\u00e0 $20\\pi $ $\\left( c{{m}^{2}} \\right)$ v\u00e0 di\u1ec7n t\u00edch to\u00e0n ph\u1ea7n l\u00e0 $28\\pi \\left( c{{m}^{2}} \\right)$.<br\/><b>C\u00e2u b:<\/b> T\u00ednh th\u1ec3 t\u00edch h\u00ecnh tr\u1ee5 <br\/><b>\u0110\u00e1p s\u1ed1:<\/b> _input_$\\pi$ $(cm^3)$ <\/span>","hint":"","explain":"<span class='basic_left'>Theo k\u1ebft qu\u1ea3 <b>c\u00e2u a<\/b>, ta c\u00f3 b\u00e1n k\u00ednh \u0111\u00e1y c\u1ee7a h\u00ecnh tr\u1ee5 l\u00e0: $R=2$$cm$ v\u00e0 chi\u1ec1u cao c\u1ee7a h\u00ecnh tr\u1ee5 l\u00e0 $h=5$$cm$<br\/> Th\u1ec3 t\u00edch h\u00ecnh tr\u1ee5 l\u00e0 $V=\\pi {{R}^{2}}h=\\pi .4.5=20\\pi \\left( c{{m}^{2}} \\right)$<br\/><span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n c\u1ea7n \u0111i\u1ec1n l\u00e0 $20.$ <\/span><\/span>"}]}],"id_ques":1677},{"time":24,"part":[{"title":"Ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[3]],"list":[{"point":5,"ques":"<span class='basic_left'>M\u1ed9t c\u1ed9t g\u1ed7 h\u00ecnh tr\u1ee5 c\u00f3 chu vi \u0111\u00e1y b\u1eb1ng $8$ $dm,$ chi\u1ec1u cao (t\u1ee9c chi\u1ec1u d\u00e0i c\u1ee7a c\u1ed9t) b\u1eb1ng $3$ $m. $T\u00ednh kh\u1ed1i l\u01b0\u1ee3ng c\u1ed9t g\u1ed7 bi\u1ebft $1$ $dm^3$ c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng $0,8$ $kg$ <\/span>","select":["A. $384$ $(kg)$ ","B. $\\dfrac{192}{\\pi}$ $(kg)$ ","C. $\\dfrac{384}{\\pi}$ $(kg)$ ","D. $384 \\pi$ $(kg)$ "],"hint":"","explain":"<span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn: <\/span><br\/>B\u01b0\u1edbc 1: T\u00ecm b\u00e1n k\u00ednh \u0111\u00e1y<br\/>B\u01b0\u1edbc 2: T\u00ednh th\u1ec3 t\u00edch $V$ kh\u00fac g\u1ed7<br\/>B\u01b0\u1edbc 3: T\u00ednh kh\u1ed1i l\u01b0\u1ee3ng kh\u00fac g\u1ed7: $V.0,8$ <br\/><span class='basic_green'>B\u00e0i gi\u1ea3i<\/span><br\/>\u0110\u1ed5i $3m=30dm$<br\/>B\u00e1n k\u00ednh \u0111\u00e1y l\u00e0: $8:2\\pi =\\dfrac{4}{\\pi }\\left( dm \\right)$ <br\/>Th\u1ec3 t\u00edch c\u1ee7a c\u1ed9t g\u1ed7 l\u00e0: $V=\\pi {{R}^{2}}h=\\pi .{{\\left( \\dfrac{4}{\\pi } \\right)}^{2}}.30=\\dfrac{480}{\\pi }\\left( d{{m}^{3}} \\right)$ <br\/>Kh\u1ed1i l\u01b0\u1ee3ng c\u1ed9t g\u1ed7 l\u00e0: $\\dfrac{480}{\\pi }.0,8=\\dfrac{384}{\\pi}\\left( kg \\right)$<br\/><span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 C<\/span><\/span>","column":2}]}],"id_ques":1678},{"time":24,"part":[{"title":"Ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[2]],"list":[{"point":5,"ques":"<span class='basic_left'>M\u1ed9t \u1ed1ng th\u1ee7y tinh h\u00ecnh tr\u1ee5 \u0111\u1ef1ng n\u01b0\u1edbc \u0111\u1eb7t nghi\u00eang. M\u1eb7t n\u01b0\u1edbc trong \u1ed1ng l\u00e0 m\u1ed9t h\u00ecnh tr\u00f2n, <b>\u0111\u00fang<\/b> hay <b>sai<\/b>?<br\/><center><img src='https://www.luyenthi123.com/file/luyenthi123/lop9/toan/hinhhoc/bai22/lv1/img\/H941_D5.png' \/><\/center><\/span>","select":["A. \u0110\u00fang ","B. Sai "],"hint":"","explain":"Kh\u1eb3ng \u0111\u1ecbnh tr\u00ean l\u00e0 <b>sai<\/b> v\u00ec m\u1eb7t n\u01b0\u1edbc trong \u1ed1ng kh\u00f4ng ph\u1ea3i l\u00e0 h\u00ecnh tr\u00f2n m\u00e0 l\u00e0 m\u1ed9t h\u00ecnh elip<br\/><span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n c\u1ea7n ch\u1ecdn l\u00e0 B<\/span><\/span>","column":2}]}],"id_ques":1679},{"time":24,"part":[{"title":"\u0110i\u1ec1n s\u1ed1 th\u00edch h\u1ee3p v\u00e0o ch\u1ed7 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank","correct":[[["942,5","942"]]],"list":[{"point":5,"width":40,"content":"","type_input":"","ques":"<span class='basic_left'>\u0110\u1ec3 \u0111o th\u1ec3 t\u00edch c\u1ee7a m\u1ed9t vi\u00ean \u0111\u00e1, ng\u01b0\u1eddi ta cho vi\u00ean \u0111\u00e1 \u0111\u00f3 v\u00e0o trong m\u1ed9t b\u00ecnh h\u00ecnh tr\u1ee5 r\u1ed3i \u0111\u1ed5 n\u01b0\u1edbc cho ng\u1eadp vi\u00ean \u0111\u00e1, khi \u0111\u00f3 m\u1ef1c n\u01b0\u1edbc trong b\u00ecnh cao $20$ $cm.$ Sau \u0111\u00f3 ng\u01b0\u1eddi ta l\u1ea5y vi\u00ean \u0111\u00e1 ra kh\u1ecfi b\u00ecnh, khi \u0111\u00f3 m\u1ef1c n\u01b0\u1edbc trong b\u00ecnh cao $17$ $cm.$ T\u00ednh th\u1ec3 t\u00edch c\u1ee7a vi\u00ean \u0111\u00e1 bi\u1ebft \u0111\u01b0\u1eddng k\u00ednh \u0111\u00e1y c\u1ee7a h\u00ecnh tr\u1ee5 l\u00e0 $20$ $cm$ (l\u00e0m tr\u00f2n k\u1ebft qu\u1ea3 \u0111\u1ebfn s\u1ed1 th\u1eadp ph\u00e2n th\u1ee9 nh\u1ea5t)<br\/><b> \u0110\u00e1p s\u1ed1:<\/b> _input_ $(cm^3)$<\/span>","hint":"Th\u1ec3 t\u00edch c\u1ee7a vi\u00ean \u0111\u00e1 s\u1ebd b\u1eb1ng th\u1ec3 t\u00edch c\u1ee7a b\u00ecnh khi m\u1ef1c n\u01b0\u1edbc trong b\u00ecnh cao $20$ $cm $ tr\u1eeb \u0111i th\u1ec3 t\u00edch c\u1ee7a b\u00ecnh n\u01b0\u1edbc khi l\u1ea5y vi\u00ean \u0111\u00e1 ra.","explain":"<span class='basic_left'>Th\u1ec3 t\u00edch c\u1ee7a vi\u00ean \u0111\u00e1 b\u1eb1ng th\u1ec3 t\u00edch c\u1ee7a m\u1ed9t h\u00ecnh tr\u1ee5 c\u00f3 \u0111\u01b0\u1eddng k\u00ednh \u0111\u00e1y $20$ $cm$ v\u00e0 chi\u1ec1u cao l\u00e0 $20-17=3$ $(cm).$ <br\/>Do \u0111\u00f3 th\u1ec3 t\u00edch c\u1ee7a vi\u00ean \u0111\u00e1 l\u00e0:<br\/>$V=\\pi {{R}^{2}}h=\\pi {{.10}^{2}}.3=300\\pi \\approx 942,5\\left( c{{m}^{3}} \\right)$ <br\/><span class='basic_pink'>V\u1eady s\u1ed1 c\u1ea7n \u0111i\u1ec1n l\u00e0 $942,5.$ <\/span><\/span>"}]}],"id_ques":1680}],"lesson":{"save":0,"level":1}}