A backyard has a swimming pool that measures 20ft by 35ft. The backyard has a perimeter of 370ft and a width of 80ft. What is the area of the backyard not including the pool?

You have to figure out the area of the backyard first by finding it's dimensions. We know that 2 of the sides are 80ft. Thus the total length of the other two sides are 210ft since 370ft - 160ft = 210ft. Obviously the length of the other two sides would be half this length since they are the same length and would be 105ft.

The area of the backyard is 80ft X 105ft = 8,400ft^2

The area of the pool is 20ft X 35ft = 700ft^2

Area of backyard without pool is 8,400ft^2 - 700ft^2 = 7,700ft^2