Question

The slant height of the frustum of a cone is 4cm and the perimeter of its circular ends are 18cm and 6cm find the csa of frustu

Answer 1

Answer:

Step-by-step explanation:2×pi×r=6

Pi×r=6/2

r=3/pi

2×pi×R=18

Pi×R=18/2

R=9/pi

CSA of frustum=pi×(r+R)×l

=pi×(3/pi +9/pi)×4

=pi×(3+9/pi)4

=pi×1/pi(12)×4

=12×4

=48cm.sq.