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 90cm

Answer 1

P of triangle = a + b = c = 90

ratio 3:4:5
so a = 3x, b = 4x , c = 5x

3x + 4x + 5x = 90
12x = 90
x = 90/12 = 7.5

a = 3x = 3 * 7.5 = 22.5
b = 4x = 4 * 7.5 = 30
c = 5x = 5 * 7.5 = 37.5

Answer:
1st side = 22.5
2nd side = 30
3rd side = 37.5

Double check: 22.5 + 30 + 37.5 = 90 (perimeter)