grade 10 · GEOM-002

Reason with a transversal

Distinguish congruent angle pairs from supplementary same-side pairs.

Learn togetherFresh problem · seed 218119894

Two parallel lines are cut by a transversal. One angle measures \(109^\circ\). What is the measure of its alternate interior partner?

Let's work it out together.

Work through one checkpoint at a time. Your answer area opens after the reasoning.

Checkpoint 1

Name the requested angle relationship before calculating.
Checkpoint 2

This angle pair is congruent when the lines are parallel.
Checkpoint 3

Check whether your result should match the known angle or complete 180 degrees.

Your answer