The figure is not drawn to scale. CEFG is a trapezium and CE // GF. Given that CG = CD, ∠GCD = 78° and ∠CEF = 102°.
- Find ∠EFG
- Find ∠CDG
- Find ∠DGF
(a)
∠EFG
= 180° - 102°
= 78° (Interior angles, CE//GF)
(b)
∠CDG
= (180° - 78°) ÷ 2
= 102° ÷ 2
= 51° (Isosceles triangle)
(c)
∠DGF
= ∠CDG
= 51° (Alternate angles, CE//GF)
Answer(s): (a) 78°; (b) 51°; (c) 51°