If two angles are complementary, then the
sum of their measures is 90 degrees.
For example, if we have a 30° angle and a 60° angle, these two angles
are complementary because the sum of their measures is 90 degrees.
If two angles are supplementary, then the
sum of their measures is 180 degrees.
For example, if we have a 100° angle and an 80° angle,
then these two angles are supplementary because
the sum of their measures is 180 degrees.