Given:
Radius of the cone = 5 ft
Slant height of the cone = 21 ft
To find:
The surface area of the cone
Solution:
Surface area of cone formula:
[tex]SA=\pi r^{2}+\pi r l[/tex]
where r is the radius and l is the slant height.
[tex]SA=\pi \times 5^{2}+\pi \times 5 \times 21[/tex]
[tex]SA=\pi \times 25+\pi \times 105[/tex]
[tex]SA=25 \pi+ 105 \pi[/tex]
[tex]SA=130 \pi[/tex]
The surface area of the cone is 130π square feet.
