Two complementary angles are in the ratio 4:5 Find the angles.
40°, 50°
Let angle = X
Complementary of X = 90° – X
According to question,
X : 90° – X = 4 : 5
⇒ X / (90° – X) = 4 / 5
⇒ 5X = 4(90° – X)
⇒ 5X = 360° – 4X
⇒ 5X + 4X = 360°
⇒ 9X = 360°
⇒ X = 40°
Therefore angle = 40°
And its supplement = 90° – 40° = 50°