PSLE BCDE and CEFG are rhombuses. DHE is a straight line.
- Find ∠ECH.
- Find ∠DEF.
(a)
∠CED
= (180° - 98°) ÷2
= 82° ÷ 2
= 41° (Isosceles triangle)
∠ECH
= 180° - 123° - 41°
= 16° (Angles sum of triangle)
(b)
∠CGF
= 360° - 281°
= 79° (Angles at a point)
∠CEF = ∠CGF = 79° (Rhombus)
∠DEF
= 79° - 41°
= 38°
Answer(s): (a) 16°; (b) 38°