Question

If length of two sides of a triangle are in the ratio 5:6:7and the perimeter is 180cm.find the measure of the 3rd side​

Answer 1

❒ GIVEN :

• Length of sides of triangle are in ratio 5:6:7
• Perimeter of triangle = 180 cm

❒ TO FIND :

• Length of 3rd side.

❒ APPROACH :

• So, in this question we are given the ratio of length of side of triangle that is 5:6:7 and the perimeter of triangle = 180cm.As we know that Perimeter of triangle = sum of all the sides. So we will be forming an equation from the given data.
• Equation so formed is 5x + 6x + 7x = 180.

Now ,lets proceed further :-

➨ 5x + 6x + 7x = 180

➨ 18x = 180

➨ x = 180 / 18

➨ x = 10

➱ Length of First side = 5x = 5 × 10 = 50cm

➱ Length of second side = 6x = 6 × 10 = 60 cm

➱ Length of third side = 7x = 7 × 10 = 70cm

Therefore,Length of third side = 70cm.

Answer 2

Question :-

If length of two sides of a triangle are in the ratio 5:6:7and the perimeter is 180cm.find the measure of the 3rd side.

Given :-

• Ratio of length of sides of a triangle = 5:6:7

• Perimeter of triangle = 180cm

To find :-

Measure of third side.

Formula used :-

Perimeter of triangle = Sum of its sides.

Solution :-

Ratio of sides of triangle = 5:6:7

Let it be 'x'

Length of first side = 5x

Length of second side = 6x

Length of third side = 7x

Perimeter of triangle = 180cm

5x + 6x + 7x = 180cm

18x = 180

x = 180/18

x = 10cm

Value of x = 10cm

✰Length of first side = 5x = 5 × 10 = 50cm

✰Length of second side = 6x = 6 × 10 = 60cm

✰Length of third side = 7x = 7 × 10 = 70cm

Therefore,

Length of third side = 70 cm

Verification :-

First side + second side + third side = 180cm

50cm + 60cm + 70cm = 180cm

180cm = 180cm

LHS = RHS

Hence verified