Question

An envelope has an area of 40 square inches and a perimeter of 28 inches. What are the dimensions of the envelope?

Answer 1

10 inches by 4 inches

Explanation:

Area of envelope, A = 40 in²

Perimeter of envelope, P = 28 in

Area = Length * width, L*W

Perimeter = 2(L + W)

40 = LW - - - (1)

28 = 2(L+W)

28/2 = L+W

14 = L+W - - - (2)

Solving like a quadratic equation ;

We need two numbers whose sum gives 14 and product gives 40

The numbers are 10 and 4

(10*4) = 40 and (10+4) = 14