The sides of a triangle are in the ratio of 7 : 9 : 12. The difference between the length of largest and smaller sides is 15 c.m. The length of the largest sides would be = ?

Answer: Option A

Sides of a triangle are in the ratio of 7 : 9 : 12
i.e. 7x : 9x : 12x
Difference between the length of largest and smaller sides = 12x - 7x = 15
⇒ x = 3
∴ largest sides would be 12 × 3 = 36cm