Question

the length of a rectangle is 3cm less than its width. The perimeter is 54 cm. What are the dimensions of the rectangle

Answer 1

The dimensions of the rectangle:

length: 12cm

width: 15 cm

Explanation:

The perimeter of a rectangle is:

perimeter = 2(length+width)

54 = 2(a+b)

a = b - 3

a = legth

b = width

then:

54 = 2((b-3)+b)

54/2 = b-3 + b

27 = 2b - 3

27 + 3 = 2b

30 = 2b

b = 30/2

b = 15

a = b-3

a = 15 - 3

a = 12

Check:

54 = 2(15+12)

54 = 2*27