PSLEIn the figure, MNPQ is a straight line, NQRS is a parallelogram and RP = RS. ∠SMN is a right angle, ∠MSN = 27° and ∠QRP = 21°.
- Find ∠t.
- Find ∠u.
(a)
∠SMN = 90° (Right angle)
∠t
= 90° + 27°
= 117° (Exterior angle of a triangle)
(b)
∠QRS = ∠QNS = 117° (Parallelogram)
∠PRS
= 117° - 21°
= 96°
∠u
= (180° - 96°) ÷ 2
= 42° (Isosceles triangle)
Answer(s): (a) 117°; (b) 42°