If an angle differ from its complement by 10∘, find the angle.
Let required angle = x∘ Then its complement angle = 90∘−x∘ ∴x−(90∘−x)=10 ⇒x−90∘+x=10∘⇒2x=10∘+90∘=100∘ ∴x=100∘2=50∘ ∴ Required angle = 50∘