In the figure, lines XY and MN
intersect at O and ∠ POY = 90°.
Also, given a : b = 2 : 3
Let a = 2x and b = 3x.
Since, ∠XOM + ∠POM + ∠POY = 180°
(Linear pair axiom)
⇒ 3x + 2x + 90° = 180°
⇒ 5x = 180° – 90°
⇒ x = 90 5 ° = 18°
∴ ∠XOM = b = 3x = 3 × 18° = 54°
and ∠POM = a = 2x = 2 × 18° = 36°
Now, ∠XON = c = ∠MOY = ∠POM + ∠POY
(Vertically opposite angles)
= 36° + 90° = 126°
Hence, c = 126° Ans.
