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.

If both pairs of opposite sides of a quadrilateral are congruent, is the quadrilateral a parallelogram? This task asks learners to determine the answer and to support their answer with a proof. The resource includes a commentary for...

This task asks learners to prove that the segment joining the midpoints of two sides of a parallelogram is both congruent and parallel to an adjacent side of the parallelogram. The activity would be good to use in a discussion about how...

This activity allows students to: 1. Identify the pairs of angles formed when a transversal intersects two lines.: 2. Measure angles Using Cabri Jr. 3. Identify relationships between pairs of angles when a transversal intersects parallel...

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.

Students explore the relationships of angles formed when two parallel or non-parallel lines are cut by a transversal. This activity investigates the terms: Transversal, corresponding angles, alternate interior angles, alternate exterior...

In this activity, students create parallel lines and a transversal, and study the properties of the lines and their angles.

Students explore relationships in various angles formed by 2 parallel lines and a transversal.

Students can use Cabri Jr. to construct parallel lines and transversals. They will make conjectures about the angles that are formed.

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

In this activity, students learn and increase their knowledge about the angles formed when parallel lines are cut by a transversal.

Using Cabri Jr, the students (with the teachers help) will create parallel lines cut by a transversal, measure angles, and compare the relationships of the angles formed using features of the Cabri Jr.

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.