Question

The lateral area of a cone is 400 pi cm^2. The radius is 10 cm. Find the slant height to the nearest tenth.

Answer 1

The slant height is 40cm.

Step-by-step explanation

The lateral area of a cone is given by:

`Area= \pi \: r \: l`

where r=10cm is the radius of the circle and l is the slant height.

It was also given that, the lateral area is 400π cm²

We substitute the values to get,

`400\pi = \pi * \: 10 * \: l`

We now divide both sides by 10π.

This implies that,

`(400 \pi)/(10\pi) = l`

`40 = l`

Hence the slant height is 40cm.