The formula for working out the area of a circle is [tex] \pi [/tex][tex] r^{2} [/tex]. r stands for the radius. The radius is the diameter divided by two.
r = d/2
r = 8cm/2
= 4cm
Now you just need to substitute r into the formula for the area of a circle:
[tex] \pi [/tex][tex] 4^{2} [/tex]
= [tex] \pi [/tex]*16
= 16[tex] \pi [/tex][tex] cm^{2} [/tex] (Remember that the area is always given in units squared, in this case cm)
≈ 50.3 [tex] cm^{2} [/tex]
