A line which cuts an angle into two equal side angles is called an angle bisector. In geometry a construction is an accurate drawing. There are two main constructions which can be done using a ...

OM is perpendicular to AB (meet at a right angle). Look at triangles OAM and OBM. The hypotenuses (OA and OB) are the same, as they are both the radius of the circle. OM is common to both triangles.