A sector of a circle of radius 5 cm is recast into a right circular cone of height 4 cm. What is the volume of the cone so formed?
Explanation:
A sector of a circle with radius 5 cm will look something like this.
When recast into a right-circular cone of height 4 cm it will look something like this.
Hence, the radius of the sector becomes the slant height of the cone. Therefore,
Base radius of the cone (r) =
Hence, r =
Volume = (1/3)*pi*r2*h
= 12*pi cm3