The diameter of a cookie is 2 inches. If
�
π = 3.14, what is the area of the cookie, rounded to the nearest tenth?
A
3
9
.
4
�
�
.
2
39.4 in.
2
B
9
.
9
�
�
.
2
9.9 in.
2
C
3
.
1
�
�
.
2
3.1 in.
2
D
6
.
3
�
�
.
2
6.3 in.
2
C
3.1 in^2
To find the area of a circle, you use the formula A = πr^2, where r is the radius of the circle. Since the diameter is given, you first need to divide it by 2 to get the radius.
Radius = diameter/2 = 2/2 = 1 inch
Now plug the radius into the formula:
A = π(1)^2
A = 3.14 * 1
A = 3.14 in^2
Rounded to the nearest tenth, the area of the cookie is 3.1 in^2.