The figure is not drawn to scale. CDFG is a parallelogram. ∠GCO is 57° and ∠FDE is 32°. CDE is an isosceles triangle and CD = DE.
- Find ∠OED.
- Find ∠CGF.
(a)
∠DOC = 57° (Alternate angles, CG//DF)
∠DOE
= 180° - 57°
= 123° (Angles on a straight line)
∠OED
= 180° - 123° - 32°
= 25° (Angles sum of triangle)
(b)
∠DCO = 25° (Isosceles triangle CDE)
∠CGF
= 180° - 57° - 25°
= 98° (Interior angles, CD//GF)
Answer(s): (a) 25°; (b) 98°