Answer:
The lengths of the sides are 12cm, 28cm and 36cm.
Step-by-step explanation:
Let the smallest side be 4x, the middle side be 7x and the largest side be 9x.
Smallest side + middle side + largest side = 60cm
4x + 7x + 9x = 60
20x = 60
x = 60 ÷ 20
x = 3
Smallest side (4x) = 3 × 4
= 12
Middle side (7x) = 7 × 4
= 28
Largest side (9x) = 9 × 4
= 36
