Question

1. The sides of a triangle are in the ratio 3:4:5 What is the length of each side if the perimeter

of the triangle is 90 cm?

Answer 1

22.5 cm, 30 cm, 37.5 cm

Explanation:

Sum the parts of the ratio, 3 + 4 + 5 = 12 parts

Divide the perimeter by 12 to find the value of one part of the ratio.

90 cm ÷ 12 = 7.5 cm ← value of 1 part of the ratio, thus

3 parts = 3 × 7.5 cm = 22.5 cm

4 parts = 4 × 7.5 cm = 30 cm

5 parts = 5 × 7.5 cm = 37.5 cm

The 3 sides are 22.5 cm, 30 cm and 37.5 cm