How do you bisect an angle?

Draw an arc on the vertex of the angle. Then draw two more arcs from the intersection of the previous arc and the two legs in the interior of the angle. Finally draw a straight line through the vertex and the intersection of the last two arcs.

1. Draw the vertex arc

   Draw an arc by placing the point of the compass on the vertex of the angle (where the two legs of the angle meet). The radius of the arc can be any length, but it is preferable to choose a moderate radius so that there is enough space for the following steps.

2. Draw two interior arcs

   Place the compass point on the cross section of the vertex arc and one leg of the angle. Then draw another arc in the interior of the angle. Repeat this step for the other leg not changing the compass setting. This radius can be the same as the vertex arc or greater, but it is preferable to use the same radius.

3. Draw the straight line

   Draw a straight line using a ruler or straightedge through the vertex of the angle and the intersection of the two interior arcs. This line is the bisection of the angle.