PSLE ABCD and BDEF are rhombuses. CGD is a straight line.
- Find ∠DBG.
- Find ∠CDE.
(a)
∠BDC
= (180° - 96°) ÷2
= 84° ÷ 2
= 42° (Isosceles triangle)
∠DBG
= 180° - 125° - 42°
= 13° (Angles sum of triangle)
(b)
∠BFE
= 360° - 285°
= 75° (Angles at a point)
∠BDE = ∠BFE = 75° (Rhombus)
∠CDE
= 75° - 42°
= 33°
Answer(s): (a) 13°; (b) 33°