Computer Assignment: Angle Bisector
Start by placing three points on the sketch. The first point should be to the left-hand side of the
screen with the other two on the other side of the screen. These points need to be non-colinear.
Label these points. The point on the left side of the screen should be called A, and the other two
points are B and C.
Step 1: Construct the ray AB and AC respectively. This means that the ray should start at point
A and pass through point B, and the second ray should start at A and pass through C.
Step 2: Construct a unit segment, DE, somewhere on the sketch.
Step 3: Construct a circle with center A and radius of your unit segment DE.
Step 4: Construct the point of intersection between the ray AB and the circle made in step 3.
Label this point F.
Step 5: Construct the point of intersection between the ray AC and the circle made in step 3.
Label this point G.
Step 6: Hide the circle from step 3.
Step 7: Construct a circle with center F and passing through G.
Step 8: Construct a circle with center G and passing through F.
Step 9: Construct the points of intersection between the circles constructed in steps 7 and 8.
Step 10: Select the point A then one of the points made in step 9, in that order. Construct the ray
that passes through these points.
Step 11: Hide the circles.
This ray is an angular bisector.
Move the points B and C around and marvel at what you behold. The ray made in step 10 should
move and always remains an angular bisector.
Save file as angbisec.
Designed by David Jay Hebert, Ph.D.