- Bài toán về hình nón - Có lời giải chi tiết

A \({S_{tp}} = \pi rl\)

B \({S_{tp}} = \pi rl + 2\pi r\)

C \({S_{tp}} = \pi rl + \pi {r^2}\)

D \({S_{tp}} = 2\pi rl + \pi {r^2}\)

A \({l^2} = {h^2} + {R^2}\)      

B \(\dfrac{1}{{{l^2}}} = \dfrac{1}{{{h^2}}} + \dfrac{1}{{{R^2}}}\)

C \({R^2} = {h^2} + {l^2}\)

D \({l^2} = hR\)

A \(12\pi \,\left( {c{m^2}} \right)\)       

B \(15\pi \,\,\left( {c{m^2}} \right)\)

C \(20\pi \,\,\left( {c{m^2}} \right)\)

D \(30\pi \,\,\left( {c{m^2}} \right)\)

A \(72\pi \,\,\left( {c{m^3}} \right)\)

B \(216\pi \,\,\left( {c{m^3}} \right)\)

C \(\sqrt {72} \pi \,\,\left( {c{m^3}} \right)\)

D \(27\pi \,\,\left( {c{m^3}} \right)\)

A \(\pi {a^2}\)

B \(\dfrac{{\pi {a^2}}}{2}\)

C \(2\pi {a^2}\)

D \(\dfrac{{\pi {a^2}\sqrt 3 }}{2}\)

A \(\dfrac{{4\pi {a^3}}}{3}\)

B \(\dfrac{{4\pi {a^3}}}{3}\)

C \(\dfrac{{8\pi {a^3}}}{3}\)

D \(\dfrac{{8\pi {a^3}\sqrt 2 }}{3}\)

A \(3\pi {a^2}\)

B \(\dfrac{5}{3}\pi {a^2}\)        

C \(\pi {a^2}\)

D \(\sqrt 3 \pi {a^2}\)

A \(6\pi {a^2}\,\,\left( {c{m^2}} \right)\)

B \(\sqrt 2 \pi {a^2}\,\,\left( {c{m^2}} \right)\)

C \(6\sqrt 2 \pi {a^2}\,\,\left( {c{m^2}} \right)\)

D \(3\sqrt 2 \pi {a^2}\,\,\left( {c{m^2}} \right)\)

A \(\sqrt 7 \pi {a^3}\,\,\left( {c{m^3}} \right)\)

B \(\dfrac{{7\pi {a^3}}}{3}\,\,\left( {c{m^3}} \right)\)

C \(2\pi {a^3}\,\,\left( {c{m^3}} \right)\)

D \(\dfrac{{2\sqrt 7 \pi {a^3}}}{3}\,\,\left( {c{m^3}} \right)\)

A \(\dfrac{{\pi {R^2}}}{2}\)

B \(\pi {R^2}\)

C \(2\pi {R^2}\)

D \(4\pi {R^2}\)

A \(48\,\,\left( {c{m^2}} \right)\)

B \(40\,\,\left( {c{m^2}} \right)\)          

C \(60\,\,\left( {c{m^2}} \right)\)

D \(100\,\,\left( {c{m^2}} \right)\)

A \(\dfrac{{\pi {a^3}\sqrt 3 }}{{27}}\)

B \(\dfrac{{\pi {a^3}\sqrt 6 }}{{27}}\)

C \(\dfrac{{\pi {a^3}\sqrt 3 }}{9}\)       

D \(\dfrac{{\pi {a^3}\sqrt 6 }}{9}\)

A \(\dfrac{{a\sqrt[3]{{2\sqrt 3 }}}}{4}\)          

B \(\dfrac{{a\sqrt[3]{3}}}{8}\)

C \(\dfrac{{a\sqrt[3]{{2\sqrt 3 }}}}{8}\)

D \(\dfrac{{a\sqrt[3]{{2\sqrt 3 }}}}{2}\)

A \(\dfrac{{9\sqrt 3 }}{2}\,\,\left( {c{m^2}} \right)\)

B \(\dfrac{{27}}{2}\,\,\left( {c{m^2}} \right)\)

C \(6\,\,\left( {c{m^2}} \right)\)

D \(3\sqrt 2 \,\,\left( {c{m^2}} \right)\)

A \(16\pi {a^3}\)

B \(\dfrac{{25}}{3}\pi {a^3}\)

C \(48\pi {a^3}\)

D \(\dfrac{{16}}{3}\pi {a^3}\)

A Vô số

B 3

C 2

D 1

A \(h = \sqrt 3 R\)

B \(h = \sqrt 2 R\)          

C \(h = \dfrac{{4R}}{3}\)

D \(h = \dfrac{{3R}}{2}\)

A \(\dfrac{{8a}}{3}\)      

B \(\sqrt 2 a\)

C \(2\sqrt 2 a\)

D \(\dfrac{{4a}}{3}\)

A \(98\pi \)

B \(106\pi \)

C \(96\pi \)

D \(86\pi \)

A \(l \approx 58,67\,\,cm\)        

B \(l \approx 58,80\,cm\)

C \(l \approx 59,98\,cm\)

D \(l \approx 61,20\,cm\)