Question

What is the radius of a circle with an area of 78.5 square inches?

Use 3.14 for pi

Answer 1

Explanation:

Let the radius of circle be r

Area of circle =

�

�

2

πr

2

Area of circle =

3.14

×

�

2

3.14×r

2

We are given that an area of 78.5 square inches

So,

3.14

×

�

2

=

78.5

3.14×r

2

=78.5

�

2

=

78.5

3.14

r

2

=

3.14

78.5

�

2

=

25

r

2

=25

�

=

25

r=

25

r=5

Hence The radius of circle is 5