George wants to build a fence around his square backyard measures 60 feet. If it cost $7 per foot for the fence and george only needs to put fencing around three sides of the yard, how much will it cost him to build the fence?

A = s2 (Area of a square is its side squared)

P = 4s (perimeter of a square is a side times 4)

A = 324 (the area of this square is 324 ft2)

fencing = $7 per foot

Let's find the side through the area. Find the root:

√324 = √s2

18 = s

Now the perimeter:

P = 4 * 18 = 72

Now to find how much the fencing will cost:

72 * 7 = 504