Question

Two straight lines AB and CD cut each other at O. If ∠BOD = 63°, then ∠BOC =

(a) 63°

(b) 117°

(c) 17°

(d) 153°

Answer 1

Let us draw the following diagram showing two linesand intersecting each other at a point.

Let the required angle measures.

Also, and form a linear pair. Therefore, their sum must be equal to.

That is,

It is given that. Substituting, this value above, we get:

Hence, the correct choice is (b).