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