Question

a=pi r*r solve this problem​

Answer 1

Answer:

The given quadratic equation A=πr

2

is the area of the circle with radius r.

Substitute A=77 and π=

7

22

in the equation A=πr

2

as follows:

A=πr

2

⇒77=

7

22

r

2

⇒77×7=22r

2

⇒22r

2

=539

⇒r

2

=

22

539

⇒r

2

=

2

49

⇒r=

2

49

⇒r=±

2

7

Since radius cannot be negative, therefore, r=

2

7

Hence, r=

2

7

.