9
9
The formula for the area of a circle is:
Area=π∗(Radius)2\text{Area} = \pi * \text{(Radius)}^{2}
The radius is the distance from the center of the circle to the edge:
radius
In this problem we have been given the diameter of the circle. The diameter is the distance from one edge of the circle to the opposite edge:
diameter
The diameter of a circle is always twice as long as the radius
In this problem, the diameter of the circle is 99
9
Radius=Diameter2\text{Radius} = \dfrac{\text{Diameter}}{\text{2}}
Radius=92\text{Radius} = \dfrac{9}{2}
Radius=4.5\text{Radius} = 4.5
4.5
To find the area of the circle, square the radius:
(4.5)2=20.25\left(4.5\right)^{2} = 20.25
Now multiply by π\pi. The number π\pi is approximately equal to 3.14.
Area=π∗(Radius)2\text{Area} = \pi * \text{(Radius)}^{2}
Area=3.14∗20.25\text{Area} = 3.14 * 20.25
Area=63.59\text{Area} = 63.59