PSLEEFGH is a parallelogram, EGJ is an equilateral triangle and GH = HJ.
- Find ∠EGH.
- Find ∠GHE.
- Find ∠JEF.
(a)
GH = HJ
Triangle GHJ is an isosceles triangle.
∠HGJ
= (180° - 142°) ÷ 2
= 38° ÷ 2
= 19° (Isosceles triangle)
∠EGH
= 60° - 19°
= 41° (Equilateral triangle)
(b)
∠EJH
= 60° - 19°
= 41° (Equilateral triangle)
∠EHJ
= 180° - 41° - 19°
= 120° (Angles sum of triangle)
∠EHG
= 360° - 142° - 120°
= 98° (Angles at a point)
∠FEG
= ∠EGH
= 41° (Alternate angles)
∠FEJ
= 60° + 41°
= 101°
Answer(s): (a) 41°; (b) 98°; (c) 101°