DEFG is a quadrilateral and ODGF is a trapezium in which OD // GF and ∠EDG = 111°, ∠DGF = 124°, ∠EFG = 68° and GF = GD. Find
- ∠DEO
- ∠GDO
- ∠DFG.
(a)
∠DEO
= 360° - 124° -111° - 68°
= 57° (Sum of angles in a quadrilateral)
(b)
∠GDO
= 180° - 124°
= 56° (Interior angles, DO//GC)
(c)
∠DFG
= (180° - 124°) ÷ 2
= 56 ÷ 2
= 28° (Isosceles triangle)
Answer(s): (a) 57°; (b) 56°; (c) 28°