PSLE ABCD is a trapezium with AB parallel to DC. AFB and EFD are straight lines and AE = EB. ∠EAD = 99°.
- Find ∠ADF.
- Find ∠BEF.
(a)
∠ADF
= 180° - 99° - 21°
= 60° (Angles sum of triangle)
(b)
∠AFD
= 74° (Alternate angles)
∠BAE
= 74° - 21°
= 53° (Exterior angle of a triangle)
∠BEF
= 180° - 53° - 53° - 21°
= 53° (Angles sum of triangle)
Answer(s): (a) 60°; (b) 53°