Question

Find the lateral area of a right circular cone whose radius is 6 feet and height is 8 feet.

48π ft2
60π ft2
96π ft2

Answer 1

the lateral area of a solid shape is simply the total surface area minus the surface area of any bases

on a cylinder, the two circular bases are subtracted from the total area to get the lateral area

now, let's consider a cylinder:

Answer 2

the lateral area is simply this part of the cylinder (notice how the bases are excluded in the shading)

Answer 3

if we "unroll" this area, we get a rectangle where the width is simply the height of the cylinder, and the length is the circumference of the circle (since the length was formerly wrapped around to make the circle)



therefore, lateral area = 2 * pi * r * h

should be straightforward from there