Question

Find the Surface Area of a cone with a slant height of 7 and a radius of 2. Leave your answer in terms of LaTeX: \piπ.

Group of answer choices

14 π


28/3 π


i 18 π


: 56\pi

Answer 1

Surface area of cone is
`18 \pi` square units

Solution:

Given that cone with a slant height of 7 and a radius of 2

To find: surface area of cone

The surface area of a cone is equal to the curved surface area plus the area of the base

The surface area of cone is given by formula:

`S. A=\pi r^(2)+\pi r l`

Where "r" is the radius and "l" is the slant height of cone

Substituting r = 2 and l = 7 in above formula,

`\begin{array}{l}{S A=\pi\left(r^(2)+r l\right)=\pi\left(2^(2)+2(7)\right)} \\\\ {S A=\pi(4+14)=18 \pi}\end{array}`

Thus surface area of cone is
`18 \pi` square units