From the given figure evaluate the value of x if AB is parallel to CD and the line t is a transversal.
20∘
∠CFE=5x (Vertically opposite angles)..... (i)
∠AEF=4x (Given)...(ii)
∠CFE+∠AEF=180∘ (Co−interior angles)......(iii)
5x+4x=180∘ ..From eq (i) and (ii)
9x=180∘
x=20∘