You have a patch of dead shrubs you want replaced with sod. But there's a hornet's nest in the middle, and therefore to avoid

getting stung you can't measure the radius or diameter to plug into the formula: area = pi r squared.

And in order to get a price quote from the landscaper you need the square footage.

You can however easily measure the circumference.

Question: what is the area of this circle of dead shrubs if the circumference is 100 ft?