PSLEIn the figure, CDEF is a parallelogram. CAF and AEB are straight lines. ∠BEF = 150°, ∠CFE = 43° and ∠CEA = 21°.
- Find ∠DEB.
- Find ∠DCE.
(a)
∠DEF
= 180° - 43°
= 137° (Interior angles)
∠DEB
= 360° - 150° - 137°
= 73° (Angles at a point)
(b)
∠FEA
= 180° - 150°
= 30°(Angles on a straight line)
∠DCE
= ∠CEF
= 30° + 21°
= 51° (Alternate angles)
Answer(s): (a) 73°; (b) 51°