Pete was asked why C must be on the perpendicular bisector of AB given that C is the same distance to A as it is to B. Pete's explanation is below. 1. What is something that Pete understands about the problem?

2. What question(s) could you ask Pete to help move his thinking forward?

Pete's explanation: "C must be on the perpendicular bisector of A and B because CD is congruent to itself because it is on both triangles. If you draw an angle bisector of ACB, it will cut it in half and be on the midpoint of AB. Meaning it is on the perpendicular bisector. "​