Question

two adjacent angles on a straight line are in ratio 5 :4.find the measure of each one of these angles

Answer 1

Let the angles be 5x and 4x

We know that sum of two adjacent angles = 180°


According to the question,

5x + 4x = 180°

9x = 180°

x = $\frac{180}{9}$

x = 20°


1st angle = 5x = 5 × 20 = 100°

2nd angle = 4x = 4 × 20 = 80°

Answer 2

First angle is 5x and second angle is 4x

In straight line sum of angles is 180

So 5x + 4x=180

9x=180

so x=20

Thus 5x=5*20=100 and 4x=4*20=80.