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° - 131° - 41°
= 8° (Angles sum of triangle)
(b)
∠CGF
= 360° - 301°
= 59° (Angles at a point)
∠CEF = ∠CGF = 59° (Rhombus)
∠DEF
= 59° - 41°
= 18°
Answer(s): (a) 8°; (b) 18°