Question

The slant height of a frustum of a cone is 4 cm and perimeter of its circular end are 18 cm and 6 cm . Find the curved surface area and volume of the frustum

Answer 1

First u have to find the two radius of frustum from the given perimeter of the ends

Answer 2

slant height ,l = 4cm

perimeter of one of the circular end=18cm
2πR =18
R =18/2 x π
R = 9/π

perimeter of anoher circular end = 6cm
2πr= 6
r = 6/2 x π
r = 3/π

curve surface area = πl(R + r)
=πl(9/π + 3/π)
=4π(9+3 / π)
=4π(12/π)
=4 x 12
=48 cm square