Answer:
The answer to your question is:
side 1 = 22.5 cm
side 2 = 30 cm
side 3 = 37.5 cm
Step-by-step explanation:
ratio = 3:4:5
Perimeter = 90 cm
First we get the sum of the numbers of the proportions
3 + 4 + 5 = 12
now divide the perimeter by the number of parts (12)
90 / 12 = 7.5
Side 1 = 3(7.5) = 22.5 cm
Side 2 = 4(7.5) = 30 cm
Side 3 = 5(7.5) = 37.5 cm
Perimeter = 22.5 + 30 + 37.5 = 90 cm