This is an important ques from the Book ML Aggarwal class 10th,, chapter – 7, ratio and proportion.

In these both questions we have to. Distribute the total sum according to given fixed ratio.

In first question we have to distribute perimeter of triangle in the given ratio and in second ques we have to distribute total angle sum in given ratio

Question 16

Solution:(i) It is given that

Perimeter of triangle = 30 cm

Ratio among sides = 7: 5: 3

Here the sum of ratios = 7 + 5 + 3 = 15

We know that

Length of first side = 30 × 7/15 = 14 cm

Length of second side = 30 × 5/15 = 10 cm

Length of third side = 30 × 3/15 = 6 cm

Therefore, the sides are 14 cm, 10 cm and 6 cm.

(ii) We know that

Sum of all the angles of a triangle = 180

^{0}Here the ratio among angles = 2: 3: 4

Sum of ratios = 2 + 3 + 4 = 9

So we get

First angle = 180 × 2/9 = 40

^{0}Second angle = 180 × 3/9 = 60

^{0}Third angle = 180 × 4/9 = 80

^{0}Hence, the angles are 40

^{0}, 60^{0}and 80^{0}.