Given a pair of parallel lines and a triangle in between, geometers prove that the sum of the interior angles is 180 degrees. This quick quest can be used as a pop quiz or exit ticket for your geometry class.

Without ever using the actual term, this exercise has the learner develop the key properties of the midsegment of a triangle. This task leads the class to discover a proof of similar triangles using the properties of parallel...

Geometric figures are perfect to use for proofs. Scholars prove conjectures about whether given points lie on a triangle and about midpoints. They use a provided dialogue among fictional students to frame their responses.

[Free Registration/Login Required] Students will answer real world problems by determing where to add the additional beam using parallel lines and transversals. Click learn more to watch a video and click challenge me to answer a...

Try these three problems about finding the measures of different angles that arise from diagrams involving parallel lines and transversals. Detailed solutions are written out for these three problems of moderate difficulty.

This file contains questions related to parallel lines cut by a transversal and the angles formed. The questions can be used to asses your students' understanding of this topic in geometry.

Read a description of intersecting lines and all about the different kinds of angles they form. Includes examples.