Question

The lateral area of a right cone which has a base diameter of four units and a height of 10 units is:

Answer 1

since it has a diameter of 4, then its radius is half that, or 2.

`\bf \textit{lateral area of a cone}\\\\ LA=\pi r√(r^2+h^2)~~ \begin{cases} r=radius\\ h=height\\ \cline{1-1} r=2\\ h=10 \end{cases}\implies LA=\pi (2)√(2^2+10^2) \\\\\\ LA=2\pi √(104)\implies LA\approx 64.076`

Answer 2

Answer:
`A = 64.076\ units^2`

Explanation:

The lateral area of right cone is calculated by the following formula

`A = \pi r *√(r^2 +h^2)`

Where r is the radius of the cone and h is the height

In this case we know that the diameter d of the base is:

`d=2r`

So the radius is:

`r=(d)/(2)\\\\r=(4)/(2)\\\\r=2\ units`

and

`h=10\ units`

So the area is:

`A = \pi*2 *√(2^2 +10^2)`

`A = 64.076\ units^2`