Find the measure of each marked angle. In Exercises 19–22, m and n are parallel. See Examples 1 and 2 .

When two lines are parallel, and a transversal intersects them, several angle relationships are formed. Corresponding angles are equal, alternate interior angles are equal, and consecutive interior angles are supplementary. Understanding these relationships is crucial for finding unknown angle measures in geometric problems involving parallel lines.

In geometry, angles can be classified into various relationships such as complementary, supplementary, and vertical angles. Complementary angles sum to 90 degrees, while supplementary angles sum to 180 degrees. Recognizing these relationships helps in solving for unknown angles when given certain angle measures.

Angle measurement is typically expressed in degrees or radians. In this context, knowing how to convert between these units and how to apply angle measurement in geometric contexts is essential. This includes using tools like protractors or applying trigonometric functions to find angle measures based on given information.