what is a corresponding angle

A corresponding angle is one that sits in the same relative position as another angle when a transversal crosses two lines. If the two lines are parallel, corresponding angles are equal.

Quick Scoop

Think of two parallel lines cut by a slanted line. The angles in matching corners are corresponding angles.

Easy way to spot them

• They are on the same side of the transversal.
• They are in matching corners.
• One is usually inside the two lines and the other is outside.

Example

If a line crosses two parallel lines and one angle is 60∘60^\circ 60∘, the corresponding angle in the matching position is also 60∘60^\circ 60∘.

Tiny note

Corresponding angles are a common geometry idea used to find missing angles and prove lines are parallel.