Finding length and width of a rectangle

Question

building rectangle. length of the base is 65 feet less than twice the width. The perimeter of this base is 860 feet. What is the dimension of the ba

Answer 1

Since we have two unknowns, we need two equations.  We are dealing with the length, width, and perimeter of a rectangle, so

 

l = 2w - 65

P = 2l + 2w

 

P = 2(2w - 65) + 2w

860 = 4w - 130 + 2w

860 = 6w - 130

990 = 6w

w = 165

 

So the width is 165 feet.  Put this into either of the original equations to find the length.