To find the area of a circle, use the following formula; A = πr^2
The radius of a circle is half the diameter.
So;
4.) 18/2 = 9
Radius = 9
(3.14)9^2
9(9) = 81(3.14)
254.34 is the area of figure #4.
5.) 12/2 = 6
A = (3.14)(6)^2
A = (3.14)(36)
113.04(2) Because there are two pizzas.
226.08
Number 4 gives the most amount of pizza. So, one 18 in. pizza.