Question

The surface area of the cone is 84π square feet. Find the slant height of the cone.

Answer 1

Answer:
`(84 ft^(2))/(r)-r`

Explanation:

The surface area of a cone is given by the following formula:

`A_(cone)=\pi r^(2)+\pi L r` (1)

Where:

`A_(cone)=84 \pi ft^(2)` is the surface area

`r` is the radius of the base of the cone (assuming it is a circumference)

`L` is the slant height

Rewriting (1):

`84 \pi ft^(2)=\pi r^(2)+\pi L r` (2)

Isolating
`L`:

`L=(84 ft^(2))/(r)-r` This is the slant height of the cone in termsof
`r`