Question

Determine the surface area of a right circular cone that has a slant height of 4 mm and aradius of 3 mm? Round your answer to the nearest whole.

Answer 1

The surface area of a right circular cone is computed as follows:

$SA=\pi rs+\pi r^2$

where r is the radius and s is the slant height of the cone.

Substituting with r = 3 mm and s = 4 mm, we get:

$\begin{gathered} SA=\pi\cdot3\cdot4+\pi\cdot3^2 \\ SA=12\pi+9\pi \\ SA=21\pi \\ SA\approx66\text{ mm}^2 \end{gathered}$