Question 149
If the lateral surface of a cone were unrolled into the plane, we would obtain a quarter of a disc with radius $8~\mathrm{cm}$. How tall is the cone?
(A) $10~\mathrm{cm}$
(B) $2 \sqrt{15}~\mathrm{cm}$
(C) $\sqrt{20}~\mathrm{cm}$
(D) $3~\mathrm{cm}$
(E) $16~\mathrm{cm}$
(A) $10~\mathrm{cm}$
(B) $2 \sqrt{15}~\mathrm{cm}$
(C) $\sqrt{20}~\mathrm{cm}$
(D) $3~\mathrm{cm}$
(E) $16~\mathrm{cm}$