In the figure, if AB || CD, then angle EFD is equal to:
(a) 50
(d) 40
(c) 20
(d) 30

Answer:
d) 40
Step-by-step explanation:
AB || CD, so ∠DCB + ∠ABC = 180 { co interior angles }
∠DCB + 70 = 180
∠DCB = 180 -70 = 110
∠FCE = ∠DCB { Vertically opposite angles }
∠FCE = 110
In triangle CFE
∠EFD + ∠CEF + ∠FCE = 180 ( sum of angles of triangle)
∠EFD + 30 + 110 = 180
∠EFD + 140 = 180
∠EFD = 180 -140
∠EFD = 40