Question

Find the curved surface area of a frustum cone whose larger and smaller radius is 4.5 and 2.4 ft. The slant height is 12.5 ft. (Use $\pi$ = 3)

• A. 258.75 ft${}^2$
• B. 248.75 ft${}^2$
• C. 238.75 ft${}^2$
• D. 228.75 ft${}^2$

Answer 1

The correct option is A 258.75 ft${}^2$

Curved surface area of a frustum cone = $\pi$(r + R)s $\Rightarrow$ ?

= 3 $\times$ (2.4 + 4.5) $\times$ 12.5

= 3 $\times$ (6.9) $\times$ 12.5

Curved surface area of a frustum cone = 258.75 ft${}^2$