The bisector of an angle (also called angle bisector) is a ray whose end point is the vertex of the angle and which divides the angle into two equal angles
Steps of construction:
(a) Draw a line PQ and take a point O on it.
(b) Taking O as centre and a convenient radius, draw an arc which intersects PQ at two points A and B.
(c) Taking A and B as centres and radius more than half of AB, draw two arcs which intersect each other at C.
(d) Join OC. Then ∠COQ is an angle of 90∘
(e) Draw ¯¯¯¯¯¯¯¯OE as the bisector of ∠COE. Thus, ∠QOE=45∘
(f) Again draw ¯¯¯¯¯¯¯¯¯OG as the bisector of ∠QOE. Thus,∠QOG=∠EOG=2212∘