The angles that occupy the same relative position at each intersection where a straight line crosses two others. If the two lines are parallel, the corresponding angles are equal.
Back
Vertical Angles
Front
Angles that are opposite each other when two lines cross, they share the same vertex.
Back
Adjacent Angles
Front
Two angles next to one another sharing the same vertex and a common side.
Back
Complementary Angles
Front
Two angles are complementary when they add up to 90 degrees.
Back
Supplemental Angles
Front
Two angles are supplemental when they add up to 180 degrees.
Back
Alternate Interior angles
Front
When two lines are crossed by another line (called the transversal), the pairs of angles on opposite sides of the transversal. Inside and Opposite.