PSLE ABCD is a rhombus. DFB and DECG are straight lines.
- Find ∠ABD.
- Find ∠DCG.
- Find ∠DFE.
(a)
∠ABD
= (180° - 110°) ÷ 2
= 35° (Isosceles triangle)
(b)
∠BCD
= ∠BAD
= 110° (Rhombus)
∠DCG
= 180° - 110°
= 70° (Angles on a straight line)
(c)
∠EBF
= ∠ABF
= 35° (Rhombus)
∠BEF
= 180° - 71°
= 109° (Angles on a straight line)
∠DFE
= 35° + 109°
= 144° (Exterior angle of a triangle)
Answer(s): (a) 35° (b) 70° (c) 144°