Question

The radius of the base of a cone is 4 cm and its height is 3 cm. Then, the total surface area of the cone is ….cm2. ​

Answer 1

Step-by-step explanation:

We have r=3 cm and h=4 cm

Let l cm be the slant height of the cone then

l

2

=r

2

+h

2

⇒l

2

=3

2

+4

2

⇒l=

25

cm=5cm

∴ Area of the curved surfaceπrl

πrlArea of the curved surface=(

7

22

×3×5)cm

2

=47.14cm

2