The figure is not drawn to scale. DE//GF and FE//HD. Triangles DHE and EFG are isosceles triangles. Find
- ∠c
- ∠d.
(a)
∠EFG = ∠EDH = 72° (FE//HD, ED//FG)
∠DEH
= (180° - 72°) ÷ 2
= 108° ÷ 2
= 54° (Isosceles triangle)
∠FEG
= 180° - 72° - 72°
= 36° (Isosceles triangle)
∠c
= 180° - 72° - 54° - 36°
= 18° (Interior angles, ED//FG)
(b)
∠d
= 180° - 27° - 18°
= 135° (Angles sum of triangle)
Answer(s): (a) 18°; (b) 135°
