PSLE In the figure, CDEF is a parallelogram. AFC and BFE are straight lines and AB = BC. ∠ABF = 30° and ∠DEF = 56°.
- Find ∠EFC.
- Find ∠FBC.
(a)
∠EFC
= 180° - 56°
= 124° (Interior angles)
(b)
∠AFB
= ∠EFC
= 124° (Vertically opposite angles)
∠BAF
= 180° - 124° - 30°
= 26° (Angles sum of triangle)
∠BCF = ∠BAF (Isosceles triangle)
∠ABC
= 180° - 26° - 26°
= 128° (Angles sum of triangle)
∠FBC
= 128° - 30°
= 98°
Answer(s): (a) 124°; (b) 98°