Question

Item 9 Find the surface area of the cone with diameter d and slant height l. Round to the nearest tenth. d=12 cm l=85mm

Answer 1

Answer: $160.28\ cm^2$

Step-by-step explanation:

Given

diameter of cone $d=12\ cm$

radius is $r=\frac{d}{2}=6\ cm$

The slant height of the cone $l=85\ mm\approx 8.5\ cm$

The surface area of a cone is

$\Rightarrow A=\pi rl$

Substitute the value

$\Rightarrow A=\frac{22}{7}\times 6\times 8.5=160.28\ cm^2$