The dimensions of circle B are twice the dimensions of circle A. The area of circle Bis 64 cm2.
What is the area of circle A?
If the area of circle B = 64*pi cm^2, it's radius must be 8 cm.
Then, the radius of circle A must be 1/2 of that = 4cm
And it's area = pi*(4cm)^2 = 16pi cm^2