Learn how to solve proofs involving parallel lines, and see examples that walk through sample problems step-by-step for you to improve your geometry proof-writing skills.

MathBitsNotebook Geometry Lessons and Practice is a free site for students (and teachers) studying high school level geometry.

Prove theorems about parallel lines. Use the Transitive Property of Parallel Lines. Theorem 3.5 below is the converse of the Corresponding Angles Theorem (Theorem 3.1). Similarly, the …

Proof by contradiction that corresponding angle equivalence implies parallel lines. Created by Sal Khan.

Introduce this activity after you’ve familiarized students with the converse of the theorems and postulates that we use in proving lines are parallel. Prepare a worksheet with several math …

This video provides a comprehensive explanation of how to prove that lines are parallel. It covers various methods, including corresponding angles and alternate interior angles, with clear …

Write an indirect proof of Theorem 9.2a,“If two coplanar lines are cut by a transversal so that the corresponding angles are congruent, then the two lines are parallel.”

Proofs. This page develops important results regarding parallel lines and transversals. Read carefully, and complete the proofs. Parallel postulate (uniqueness of parallels): Given a line …

This geometry video tutorial explains how to prove parallel lines using two column proofs. This video contains plenty of examples and practice problems for ...

On the page Angles and Parallel Lines, we saw four major pairs of angles associated directly with parallel lines and the theorems stating each pairs status given the lines to be parallel.