PSLE NPQR and PRST are rhombuses. QUR is a straight line.
- Find ∠RPU.
- Find ∠QRS.
(a)
∠PRQ
= (180° - 108°) ÷2
= 72° ÷ 2
= 36° (Isosceles triangle)
∠RPU
= 180° - 129° - 36°
= 15° (Angles sum of triangle)
(b)
∠PTS
= 360° - 279°
= 81° (Angles at a point)
∠PRS = ∠PTS = 81° (Rhombus)
∠QRS
= 81° - 36°
= 45°
Answer(s): (a) 15°; (b) 45°