Answer:
22.5 cm, 30 cm, 37.5 cm
Step-by-step 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
