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

Question

Philoid · Accepted Answer

100°, 80°

Explanation:

EOF is a straight line and its adjacent angles are ∠EOB and ∠FOB.

Let ∠EOB = 5a, and ∠FOB = 4a

∠EOB + ∠FOB = 180° (EOF is a straight line)

⇒5a + 4a = 180°

⇒9a = 180°

⇒ a = 20°

Therefore, ∠EOB = 5a

= 5 × 20° = 100°

And ∠FOB = 4a

= 4 × 20° = 80°