In Fig. 6.41, if AB || DE, ∠ BAC = 35° and ∠ CDE = 53°, find ∠ DCE.
It is given in the question that:
AB parallel DE,
∠BAC = 35o
And,
∠CDE = 53o
According to question,
∠BAC = ∠CED (Alternate interior angles)
Therefore,
∠CED = 35o
Now,
∠DCE + ∠CED + ∠CDE = 180o (Sum of the interior angles of the triangle)
∠DCE + 35o + 53o = 180o
∠DCE + 88o = 180o
∠DCE = 92o