In the figure, YBEH is a rectangle, EFHJ is a rhombus and BCDE is a parallelogram. ∠EFH = 80° and ∠DEF = 91°.
- Find ∠AEB
- Find ∠EDC
(a)
∠HJE = ∠HFE = 80°
∠JEH
= (180° - 80°) ÷ 2
= 100° ÷ 2
= 50° (Isosceles triangle)
∠AEB
= 90° - 50°
= 40°
(b)
∠BED
= 360° - 91° - 90° - 50°
= 129° (Angles at a point)
∠CDE
= 180° - 129°
= 51° (Interior Angles, BE//CF)
Answer(s): (a) 40°; (b) 51°