PSLEIn the figure, LMNP is a straight line, MPQR is a parallelogram and QN = QR. ∠RLM is a right angle, ∠LRM = 31° and ∠PQN = 13°.
- Find ∠s.
- Find ∠t.
(a)
∠RLM = 90° (Right angle)
∠s
= 90° + 31°
= 121° (Exterior angle of a triangle)
(b)
∠PQR = ∠PMR = 121° (Parallelogram)
∠NQR
= 121° - 13°
= 108°
∠t
= (180° - 108°) ÷ 2
= 36° (Isosceles triangle)
Answer(s): (a) 121°; (b) 36°