The perimeter of the base of a cone is 44 cm and the slant height is 25 cm. Find the volume and the curved surface of the cone.
The perimeter of the base of a cone is 44 cm and the slant height is 25 cm. Find the volume and the curved surface of the cone.

Solution:

Given perimeter of the base of a cone = 44 cm

2r = 44

2×22/7×r = 44

r = 44×7/(2×22)

r = 7 cm

Slant height, l = 25

height, h = √(l2-r2)

h = √(252-72)

h = √(625-49)

h = √576

h = 24 cm

Volume of the cone, V = (1/3)r2h

V = (1/3)×(22/7)×72×24

V = (22/7)×49×8

V = 22×7×8

V = 1232

Hence the volume of the cone is 1232 cm3.

Curved surface area of the cone = rl

(22/7)×7×25

= 22×25

= 550 cm2

Hence the curved surface area of the cone is 550 cm2.