Corresponding Angles (Transversal)
Definition

Corresponding angles are angles that are in the same position relative to lines intersected by a transversal.


Examples

In each illustration below, LINE 1 is a transversal of LINE 2 and LINE 3. In each illustration below, the following angles are corresponding angles:

Video does not play in this browser or device. Please try another device or upgrade your browser.

Theorem

When a transversal intersects two lines, the two lines are parallel if and only if corresponding angles are congruent (equal in measure).


In illustration one of the example section above, LINE 1 and LINE 2 are parallel and corresponding angles are congruent.

In illustration two of the example section above, LINE 1 and LINE 2 are NOT parallel and corresponding angles are NOT congruent.


Demonstration
Image only

Instructions text as in global.js
Your browser does not support the canvas element.