GeoGebra Worksheet: BISECTING AN ANGLE

1. Uncheck VIEW-AXES.
   
   
2. Select OPTIONS-LABELING-NEW POINTS ONLY.
   
   
3. Use the ray tool to create an angle to bisect.
   The vertex should be labeled A.
   The point on the upper side should be renamed P;
   this point will be used later to change the original angle.
   Hide the point on the lower side.
   You should be looking at something like this:
   
   
4. Pick an appropriate radius (say, 3) and use the "Circle with center and radius" tool to construct a circle with center A.
   Mark the intersections points B and C, as shown below:
   
5. Pick an appropriate radius (say, 1.5) and use the "Circle with center and radius" tool to construct two circles, with centers B and C, each with this chosen radius.
   Mark the intersection point D, as shown below:
   
   
6. Use the "Input:" field to measure two angles:
   mofang1 = angle[D,A,C]
   mofang2 = angle[B,A,D]
   
   
7. Put in the ray through A and D.
   Clean things up, hiding all auxiliary objects.
   Put in the dynamic text shown below: