Handout
CK-12 Foundation

Ck 12: Geometry: Angles and Transversals Study Guide

For Students 9th - 10th Standards
This study guide on angles and transversals covers key terms, angle types formed by transversals, postulates and theorems about transversals, and how to prove if lines are parallel or perpendicular. It is available for download with free...
Lesson Plan
Illustrative Mathematics

Illustrative Mathematics: 8.g.a Triangle's Interior Angles

For Teachers 8th Standards
In this task, 8th graders are presented with a drawing of two parallel lines with a triangle touching them at all three of its vertices. They are asked to prove that the sum of the triangles' angles equals 180 degrees. Aligns with 8.G.A.5.