DEFG is a quadrilateral and ODGF is a trapezium in which OD // GF and ∠EDG = 111°, ∠DGF = 128°, ∠EFG = 62° and GF = GD. Find
- ∠DEO
- ∠GDO
- ∠DFG.
(a)
∠DEO
= 360° - 128° -111° - 62°
= 59° (Sum of angles in a quadrilateral)
(b)
∠GDO
= 180° - 128°
= 52° (Interior angles, DO//GC)
(c)
∠DFG
= (180° - 128°) ÷ 2
= 52 ÷ 2
= 26° (Isosceles triangle)
Answer(s): (a) 59°; (b) 52°; (c) 26°