Question

The cone shown has a diameter of 18 m and a slant height of 15 m which choice is closest to the lateral surface area

Answer 1

`423.9 m^2` is the required lateral surface area of the cone.

Explanation:

The lateral surface area of cone is:

`\pi\cdot r√(h^2+r^2)`

Slant height is l which is
`l=√(h^2+r^2)`

We have given diameter 18 m

Since, radius is half of diameter so r=18/2 =9

Slant height l =15

`\pi=3.14`

On substituting the values in the formula we get:

`3.14\cdot 9\cdot 15`

On simplification we get:

`3.14\cdot 135`

Further simplification will give:

`423.9 m^2` is the required lateral surface area of the cone.