Angle Bisectors

The angle bisector is the line that passes through the vertex of the angle and divides it into two equal parts.

Angle Bisector

Drawing Angle Bisectors I

1Draw an arc corresponding to the angle by using the vertex as the pivot point for the compass.

2From both ends of the drawn arc (where the arc meets the arms of the angle), draw equal arcs from each of the intersecting points.

3Draw a straight line from the point of intersection of the arcs and the vertex of the angle.

Angle Bisector

Drawing Angle Bisectors II

1.Draw a circle of any size using the vertex of the angle as the centre of the circle.

2.At the point of intersection of the circle and the arms of the angle, draw two smaller circles with the same radius.

3.The line that passes through the vertex of the angle and one of the points of intersection of the circles is the angle bisector.

Angle Bisector


Angle Bisectors of a Triangle

The angle bisectors of a triangle are each one of the lines that divide an angle into two equal angles.

Incenter

Incenter

The incenter is the point of intersection of the three angle bisectors.

The incenter is the center of the circle inscribed in the triangle.