Question

A cone has a circular base of radius 8m and a height of 15 m. Find the curved surface area of the
cone.​

Answer 1

Step-by-step explanation:

When two cones of same base are joined together, the surface of the shape formed will only have the curved surfaced areas visible.

We know that curved surface area of a cone =πrl where r is the radius of the cone and l is the slant height.

As both the cones have the same base and height, they are identical and their curved surface areas are equal.

Hence, surface area of this shape = Curved surface area of Cone 1 + Curved surface area of Cone 2=2×(πrl)

Given, r =c cm and h =15 cm

⇒l=

r

2

+h

2

=

8

2

+15

2

=

64+225

=17 cm

Surface area of this shape =2×(πrl)=2×

7

22

×8×17≅855cm

2