For example, you might measure an angle that is 160 degrees wide. Remember that protractors have two sets of numbers. To know which set of numbers to look at, think about the size of the angle. Obtuse angles are greater than 90 degrees, and acute angles are less than 90 degrees.
For example, if the angle is 160 degrees, you would calculate 1602=80{\displaystyle {\frac {160}{2}}=80}. So, the angle bisector is at the 80-degree mark of the angle.
For example, if the bisector of a 160-degree angle lies at the 80-degree point, you would find the 80-degree mark on the protractor and draw a point at this location in the angle’s interior.
For example, you might have angle BAC. Place the compass tip on point A. Swing the compass so that it draws an arc intersecting ray AB at point D, and ray AC at point E.
For example, place the compass tip on point D and draw an arc inside the angle.
For example, place the compass tip on point E and draw an arc intersecting the first interior arc. Label the point of their intersection point F.
For example, use a straightedge to draw a line connecting points F and A.
