Question

A cone-shaped megaphone has a radius of 15 centimeters and a slant height of 20 centimeters. A megaphone has an open bottom. What is the lateral surface area of the megaphone, in square centimeters? Use 3.14 for pi.

Answer 1

Lateral surface area of a cone = π r l. Here r = 15 cm, l = 20 cm, so area = π(15)(20) = 300π. Using π = 3.14 gives 300 × 3.14 = 942 cm².