A circle has an area of 78.5 square inches. What is the diameter of the circle?

We have to know the formula to finding the area of a circle. Since the area is clearly rounded, we can use 3.14 for pi.

R^2•3.14=78.5

Let’s divide both sides by 3.14.

R^2=25

5•5

5

So the radius is 5. The diameter is double the radius. The diameter of the circle is 10.