Question

The area of the rubber coating for a flat roof was 96 ft². The rectangular frame the carpenter built for the

flat roof has dimensions such that the length is 4 ft longer than the width. What are the dimensions?

Answer 1

Length = 12 ft.

Width = 8 ft.

Explanation:

Given :

• Area = 96 ft²
• Length = Width + 4 ft.

Let :

• Length = (x + 4) ft.
• Width = x ft.

Solving :

• The formula for calculating area is : Area = Length x Width
• 96 = (x + 4)(x)
• x² + 4x - 96 = 0
• x² + 12x - 8x - 96 = 0
• x(x + 12) - 8(x + 12) = 0
• (x - 8)(x + 12) = 0
• x - 8 = 0 ⇒ x = 8

The dimensions are :

Length = 12 ft.

Width = 8 ft.