IM Geometry Unit 2 Lesson 12 Cool Down
Elena wants to prove that a quadrilateral with 4 right angles must have congruent opposite sides. Explain to Elena how she can use the fact that all rectangles are parallelograms in her proof.
IM G Unit 2 Lesson 12 from IM Geometry by Illustrative Mathematics, https://im.kendallhunt.com/HS/students/2/2/12/index.html. Licensed under the Creative Commons Attribution 4.0 license, https://creativecommons.org/licenses/by/4.0/.