use the correct formula to find the area of a circle if the diameter is 21 mi round to the nearest hundreths place
The formula to find the area of a circle is A = πr^2, where r is the radius of the circle. Since the diameter is given, we can first find the radius by dividing the diameter by 2:
Radius = Diameter / 2 = 21 mi / 2 = 10.5 mi
Now, we can substitute the radius into the formula to find the area:
A = π(10.5)^2
A = π(110.25)
A ≈ 345.55 mi^2
Therefore, the area of the circle when the diameter is 21 mi is approximately 345.55 square miles.