Question

The angle of a sector of a circle with radius 42cm is 120 degree.if the sector is cut out and used to make a cone,what is the curved surface area of the cone?

Answer 1

So in effect the third of our circle becomes the curved surface area of the cone
( 120° = (1/3) of 360°)

area = (1/3)π 42^2 = 588π cm^2