Diện tích hình nón, thể tích khối nón !!

A.AB,OA

B.AB,OB        

C.OA,OB

D. OB,OA

A.\(2\alpha \)

B. \(\alpha \)

C. \(\frac{\alpha }{2}\)

D. 4 \(\alpha \)

A. \[\alpha = {0^0}\]

B. \[\alpha = {50^0}\]

C. \[\alpha = {90^0}\]

D. \[\alpha = {180^0}\]

A.Một hình trụ

B.Một hình nón

C.Một hình nón cụt        

D.Hai hình nón

A.\[{S_{xq}} = \frac{1}{3}\pi rl\]

B. \[{S_{xq}} = \pi {r^2}l\]

C. \[{S_{xq}} = \pi rl + \pi {r^2}\]

D. \[{S_{xq}} = \pi rl\]

A.\[12({m^2})\]

B. \[12\pi (c{m^3})\]

C. \[12\pi (c{m^2})\]

D. \[4\pi (c{m^2})\]

A.\[l = \frac{{r.{S_{xq}}}}{\pi }\]

B. \[l = \frac{{{S_{xq}}}}{{2\pi r}}\]

C. \[l = \frac{{{S_{xq}}}}{{\pi r}}\]

D. \[l = \frac{{3{S_{xq}}}}{{\pi r}}\]

A.\[{S_{tp}} = \pi rl + \pi {r^2}\]

B. \[{S_{xq}} = \pi rl + 2\pi {r^2}\]

C. \[{S_{xq}} = \pi rh + \pi {r^2}\]

D. \[{S_{xq}} = 2\pi rh\]

A. r = h  

B. h = l

C. \[{r^2} = {h^2} - {l^2}\]

D. \[{l^2} = {r^2} + {h^2}\]

A.\[3\pi \]

B. \[1 + \sqrt 5 \pi \]

C. \[\left( {\sqrt 3 + 1} \right)\pi \]

D. \[\left( {\sqrt 5 + 1} \right)\pi \]

A.\[2\pi (c{m^2})\]

B. \[4\pi (c{m^2})\]

C. \[3\pi (c{m^2})\]

D. \[6\pi (c{m^2})\]

A.\[V = \frac{1}{3}\pi rl\]

B. \[V = \frac{1}{3}\pi {r^2}l\]

C. \[V = \frac{1}{3}\pi {r^2}h\]

D. \[V = \frac{1}{3}\pi rh\]

A.\[V = \frac{1}{3}\pi r\sqrt {{l^2} - {r^2}} \]

B. \[V = \frac{1}{3}\pi {r^2}l\]

C. \[V = \frac{1}{3}\pi {r^2}\sqrt {{l^2} + {r^2}} \]

D. \[V = \frac{1}{3}\pi {r^2}\sqrt {{l^2} - {r^2}} \]

A.\[4\pi c{m^3}\]

B. \[\frac{4}{3}\pi c{m^3}\]

C. \[2\pi c{m^3}\]

D. \[6\pi c{m^3}\]

A.\[V = \frac{1}{3}{S_d}.l\]

B. \[V = \frac{1}{3}{S_d}\sqrt {{h^2} - {r^2}} \]

C. \[V = \frac{1}{3}{S_d}\sqrt {{l^2} - {r^2}} \]

D. \[V = {S_d}\sqrt {{l^2} - {r^2}} \]

A.\[\frac{{\pi {a^2}\sqrt 3 }}{4}\]

B. \[2\pi {a^2}\]

C. \[\frac{{\pi {a^2}}}{2}\]

D. \[\frac{{\pi {a^2}}}{4}\]

A.\[h = \sqrt 3 \]

B. \[h = \frac{{\sqrt 3 }}{3}\]

C. \[h = \frac{{\sqrt 3 }}{2}\]

D. \[h = 3\sqrt 3 \]

A.3     

B.\[\frac{{3\sqrt 3 }}{4}\]

C. \[\frac{{\sqrt 3 }}{2}\]

D. \[\frac{{3\sqrt 3 }}{2}\]

A.\[\tan \varphi = \frac{{\sqrt 5 }}{5}\]

B. \[\cot \varphi = \frac{{\sqrt 5 }}{5}\]

C. \[\cos \varphi = \frac{{2\sqrt 5 }}{5}\]

D. \[\sin \varphi = \frac{{2\sqrt 5 }}{5}\]

A.\[\frac{{8a}}{3}\]

B. \[\sqrt 2 a\]

C. \[2\sqrt 2 a\]

D. \[\frac{{4a}}{3}\]

A.\[l = \frac{{\sqrt 5 a}}{2}\]

B. \[l = 2\sqrt 2 a\]

C. \[l = \frac{{3a}}{2}\]

D. l = 3a .

A.\[h = R\sqrt 3 \]

B. \[h = R\sqrt 2 \]

C. \[h = \frac{{4R}}{3}\]

D. \[h = \frac{{2R}}{3}\]

A.Vô số

B.3

C.2

D.1

A.\[V = \frac{{\pi {a^3}}}{{2\sqrt 5 }}\]

B. \[V = \frac{{\pi {a^3}}}{{\sqrt 5 }}\]

C. \[V = \frac{{\pi {a^3}}}{{10\sqrt 5 }}\]

D. \[V = \frac{{\pi {a^3}}}{{5\sqrt 5 }}\]

A.\[\frac{h}{r} = 3\]

B. \[\frac{h}{r} = 2\]

C. \[\frac{h}{r} = \frac{4}{3}\]

D. \[\frac{h}{r} = \frac{{16}}{3}\]

A.\[\frac{{2\sqrt 3 }}{\pi }\]

B. \[\frac{{\sqrt 3 }}{{2\pi }}\]

C. \[\frac{{\sqrt 3 }}{\pi }\]

D. \[\frac{4}{{\pi \sqrt 3 }}\]

A.\[\frac{{7\pi }}{3}\]

B. \[\frac{{7\pi }}{6}\]

C. \[\frac{{14\pi }}{3}\]

D. \[\frac{{14\pi }}{9}\]

A.\(\pi \)

B. \[\frac{5}{3}\pi \]

C. \[\frac{4}{3}\pi \]

D. \[\frac{2}{3}\pi \]