Q. 344.5( 4 Votes )

The circumference of a circle whose area is 81πr2, is
A. 9πr

B. 18πr

C. 3πr

D. 81πr

Answer :

Let the radius of the circle be R

Area of circle = πR2

81 πr2 = πR2

R = r

R = 9r

Circumference = 2 πr


2 π(9r)

18 πr

Rate this question :

How useful is this solution?
We strive to provide quality solutions. Please rate us to serve you better.