Radius of the circle

Question

Area 78.5 sq feet what is the radius. Please be gentle I'm just,the,Nana

Area 78.5 sq feet what is the radius. Please be gentle I'm just,the,Nana

Answer 1

78.5 = πr²

24.98732607 = r²

4.998732446 = r

Answer 2

The area of a circle has the formula

1. area = π r² where r is the radius

We know the area is 78.5

1. 78.5 = π r²

If we want to solve for r, we first have to get rid of pi, so we bring pi to the other side by dividing it.

1. 78.5/π =r²
2. Using a calculator this is about 25. We want to find r, not r² so we have to get rid of the square by taking the square root of both sides.
3. The square root of 25 is 5
4. 5 =r
5. 5 ft is the radius

In shorter words, when we have the area of a circle, and we want the radius, first divide by pi (π), then take the square root of that number.

If they happen to ask for the diameter instead of he radius, just multiply the radius you got by 2, because the diameter is just 2 times the radius.