The center of the circle in the graph is located at point (-1, 3). The point (3, 3) is on the circumference of the circle. What is the approximate area of the circle if you use 3.14 for pi?

Answer 1

In order to find the area of the circle you need to know the radius. The measure of the radius is the distance from the center of the circle to any point on the circumference, in this case (3,3). The center and the given point happen to be on the same horizontal line (y=3) so the distance between them is just the change in x.

r= |-1 - 3| = 4

or

r = |3-(-1)| = 4.

For a similar problem you might have to use the distance formula to find the radius.

A = π(4)²= 16π

Substitute 3.14 for π to get an approximation for the area.