radius is normally used for a circle
in a circle, radius is the distance form the center of the circle to the outer edge of the circle
area=legnth times width or in square area=legnth times legneth
since this is a square and this is a math problem, we will assume that radius=1/2legnth so
if radius=16 then legnth =2 times 16=32
area=32 times 32=1042
area=1042 square cm or 1042 cm^2