PSLE ABCD is a rhombus. DFB and DECG are straight lines.
- Find ∠ABD.
- Find ∠DCG.
- Find ∠DFE.
(a)
∠ABD
= (180° - 108°) ÷ 2
= 36° (Isosceles triangle)
(b)
∠BCD
= ∠BAD
= 108° (Rhombus)
∠DCG
= 180° - 108°
= 72° (Angles on a straight line)
(c)
∠EBF
= ∠ABF
= 36° (Rhombus)
∠BEF
= 180° - 64°
= 116° (Angles on a straight line)
∠DFE
= 36° + 116°
= 152° (Exterior angle of a triangle)
Answer(s): (a) 36° (b) 72° (c) 152°