Mary wants to build a fence in the yard to keep her dog from running away. She only has 60 feet of fencing. If she wants to create a rectangular space that has a length that is twice as long as the width. How long is each side of the rectangular space?

1 answer

Let x = width
Let 2x = length

Perimeter of rectangle:
P = 2*(length + width)

Substitute:
60 = 2*(2x + x)
60 = 2*3x
60 = 6x
x = 10 ft (width)
2x = 20 ft (length)