Question

. A piece of paper having the form of a quadrant of a circle of radius 14 cm is rolled up to form a cone. Find ( a ) radius of its base ( b ) curved surface area of the cone.

Answer 1

radius of the circle=14

now it's a quadrant (circle is divided into 4 parts)

so height and radius of 1 part will be 14 cm and circumference will be 2πr=2×22/7×14=88(its a quadrant so divided by 4)

=88/4

=22(this is the circumference of the base of the cone and circumference of 1 part of the circle)

Cone:

2πr=22

r=22×7)22×2

=7/2

=3.5 cm

length=14cm

now CSA of cone = πrl

=22/7×3.5×14

=154 cm ²

HOPE IT HELPS