Suppose the area of a circle is 78.5 square units, what process would you use to find its radius? Then find the radius.

So we have to remember that the formula for the area of a circle is C=2πr or πd, which mean the same thing, 2 x r = d, if it makes sense.

I would use C=πd, just because it would make the process less confusing

Lets use 3.14 for π

C=πd

C/π = d

d/2 = r

78.5 = (3.14)(d)

78.5/3.14 = d

25.0 = d

25/2 = 12.5=r