Question

The sides of a triangle are in the ratio 1 : 3 : 5 and its perimeter is 90 cm. The length of its largest side is

Options

• 40 cm

• 50 cm

• 36 cm

• 54 cm

Answer 1

50 cm
The sides of the triangle are in the ratio 1:3:5.
Let x be any number such that the sides are 1x cm, 3x cm and 5x cm.
1x + 3x + 5x = 90
⇒ 9x = 90
​⇒ x = `90/9` = 10
First side = 1x = 1 ​× 10 = 10 cm
Second side = 3x = 3 ​× 10 = 30 cm
Third side = 5x = 5 × 10 = 50 cm
The length of the largest side is 50 cm.