7
7
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 77
7
Radius=Diameter2\text{Radius} = \dfrac{\text{Diameter}}{\text{2}}
Radius=72\text{Radius} = \dfrac{7}{2}
Radius=3.5\text{Radius} = 3.5
3.5
To find the area of the circle, square the radius:
(3.5)2=12.25\left(3.5\right)^{2} = 12.25
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∗12.25\text{Area} = 3.14 * 12.25
Area=38.47\text{Area} = 38.47