Question

the area of a circle with radius r is given by the formula A=πr^2. if a circle has area 64π square inches, what is the radius?

Answer 1

You have been given A = 64*pi
and also that A = pi*r^2 .
plug in value of A in the above equation , that gives you
64*pi = pi*r^2
divide both sides of equation by pi, which gives you
64 = r^2
therefore , \[r=\sqrt{64}\] inches