Question

Find the slant height of a frustum cone whose top radius is 10 ft and bottom radius is 4 ft. The height of the cone is 8 ft.

• A. 15 ft
• B. 12 ft
• C. 10 ft
• D. 14 ft

Answer 1

Answer: (C)

10 ft

Slant height, $L^2=h^2+(R-r{)}^2$

$L^2=8^2+(10-4{)}^2$

$L^2=64+36$

$L^2=100$

Squaring on both sides, we get

L = 10 ft