Draw a right angle and construct its bisector.
Steps of Construction-
1. Draw a line PQ and take a point O on it.
2. Taking O as centre and convenient radius, draw an arc which intersects PQ at A and B.
3. Taking A and B as centers and radius more than half of AB, draw two arcs which intersect each other at C.
4. Join OC. Thus, ∠COQ is the required right angle.
5. Taking B and E as centre and radius more than half of BE, draw two arcs which intersect each other at the point D.
6. Join OD. Thus, OD is the required bisector of ∠COQ.