In ∆QTR,∠QTR + ∠r + 40° = 180°| ∠ Angle sum property of a triangle⇒ 90° + ∠x + 40° = 180°⇒ ∠r + 130° = 180°⇒ ∠x = 180° - 130° = 50°∠x = 50°In ∠PSR,y° = x° + 30°| Exterior angle theorem= 50° + 30°= 80°⇒ y = 80°