IM G Unit 2 Lesson 1 Cool Down
Triangle A'B'C' is a reflection of triangle ABC across line BC. Prove that ray BC is the angle bisector of angle ABA'.
IM G Unit 2 Lesson 1 Cool Down from IM Geometry by Illustrative Mathematics, https://im.kendallhunt.com/HS/students/2/2/1/index.html. Licensed under the Creative Commons Attribution 4.0 license, https://creativecommons.org/licenses/by/4.0/.