Question

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?
22.5 cm, 30 cm, and 37.5 cm
19.3 cm, 25.7 cm, and 32.1 cm
7.5 cm, 11.5 cm, and 32.1 cm
10.5 cm, 11.5 cm, and 12.5 cm

Answer 1

the sides are 22.5cm, 30cm and 37.5cm

Answer 2

A. 22.5 cm, 30 cm, and 37.5 cm

Explanation:

If three sides of a triangle are in the ratio 3:4:5, then the lengths of the sides are 3x cm, 4x cm and 5x cm.

The preimeter of the triangle is the sum of the lengths of all sides, thus

`3x+4x+5x=90\\ \\12x=90\\ \\x=(90)/(12)=(30)/(4)=7.5\ cm`

So, the lengths of the triangle's sides are

`3x=3\cdot 7.5=22.5\ cm\\ \\4x=4\cdot 7.5=30\ cm\\ \\5x=5\cdot 7.5=37.5\ cm`