PSLEIn the figure, CDEF is a parallelogram. CAF and AEB are straight lines. ∠BEF = 153°, ∠CFE = 45° and ∠CEA = 20°.
- Find ∠DEB.
- Find ∠DCE.
(a)
∠DEF
= 180° - 45°
= 135° (Interior angles)
∠DEB
= 360° - 153° - 135°
= 72° (Angles at a point)
(b)
∠FEA
= 180° - 153°
= 27°(Angles on a straight line)
∠DCE
= ∠CEF
= 27° + 20°
= 47° (Alternate angles)
Answer(s): (a) 72°; (b) 47°