Vertical Angles are congruent.
When two lines intersect, the vertical angles are congruent. In this case, angles 1 / 4 and angles 2 / 3 are congruent.
Angles that share the same vertex and a common side are called Adjacent Angles.
Above we have an example of two adjacent angles.
Two angles are Complementary Angles if they sum to 90 degrees.
Above we have an example of two complementary angles.
Two angles are Supplementary Angles if they sum to 180 degrees.
Above we have an example of two supplementary angles.