Hello Judith,
We need to find Area (A) of a circle. Formula for area of a circle is A = πr2.
d = 2r
d/2 = r (divide both sides by 2)
8/2 = r (given d = 8)
4 = r or r = 4cm
Now substitute the value of r in A = πr2
A = 3.14 * 4 * 4
A = 50.24cm2 (answer)