Answer :
A = pi r^2
531 = 3.14 ( r^2)
169.12 = r ^2
Take the square root
13 = r
Diameter = 2r
D = 2(13)
D = 26 mm
531 = 3.14 ( r^2)
169.12 = r ^2
Take the square root
13 = r
Diameter = 2r
D = 2(13)
D = 26 mm