What are congruent angles?

Congruent angles are defined as angles that have the same measure. This means if you measure two angles and find that both have the same degree measurement, then those angles are congruent. For example, if one angle measures 30 degrees and another also measures 30 degrees, they are congruent because they are equal in measure.

In the context provided, the other options do not align with this definition. Perpendicular angles specifically refer to angles that intersect to form right angles (90 degrees) but do not necessarily share the same measure. Angles that have different measures cannot be congruent by definition. Complementary angles are those that add up to 90 degrees, which again differs from the notion of congruence that pertains specifically to equality in measure rather than a relationship of addition. Therefore, the notion of congruency is solely focused on angles having the same measure, making this the correct understanding.