Bisecting an Angle

           An angle bisector divides an angle into equal angles. If the angle is 'θ', the two angles made after bisecting will be 'θ/2'. Angle bisectors can be constructed for an acute angle, obtuse angle, or a right angle too. This angle bisector passes through the vortex of an angle, as shown in the figure.

Problem: To bisect a given Angle ABC

1. Let us consider some angle ∠ABC, B as vortex,

2. Take some length in compass and place your compass on the vertex of the angle, here on point B. Draw an arc that crosses both sides of the angle, lines AB and BC. Mark those points as D,E as shown,

3. Place your compass on one of the intersection points (i.e., D) and draw an arc inside the angle. Do not adjust the compass,

4. Place your compass on the other intersection point (i.e., E) and draw an arc that cuts the previously drawn arc as shown,

5. Mark the intersecting point of arc's as F. Finally, draw a line connecting the vortex B and point F. This is the angular bisector of our angle ∠ABC.

6. You can measure both sides of the angle to check they are equal.