Bisect This

Here is an angle:
  1. Estimate the location of a point D so that angle ABD is approximately congruent to angle CBD.
  2. Use compass and straightedge tools to create a ray that divides angle CBA into 2 congruent angles. How close is the ray to going through your point D?
Take turns with your partner, drawing and bisecting other angles.
  1. For each angle that you draw, explain to your partner how each straightedge and compass move helps you to bisect it.
  2. For each angle that your partner draws, listen carefully to their explanation. If you disagree, discuss your thinking and work to reach an agreement.