A= pi r*2 solve for A

Answer 1

A stands for the area of a circle, r is its radius and pi is what you get when you divide its circumference by its diameter (roughly 3.14). So find the radius by measuring the distance from the center of your circle to the outer ring, then square it (multiply it by itself) and multiply by 3.14.

Answer 2

Area = A = pir^2

r^2 = A/pi

r=sqr(A/pi). that solves for r= radius

the given equation though is already solved for A= area of a circle with radius = r