We have two scenarios in which we learn angle relations:[br]two lines intersecting, and two parallel lines with a transversal. (so two parallel lines with another line cutting across them)

Supplementary Angles are any angles that add to 180.[br]If the two angles sit on the same line (such as above), we also call them "Straight Angles" because they sit on a straight line.

Vertically Opposite Angles are located at the intersection of two lines, on opposite sides of the cross.[br]Unlike Straight Angles, they do not share a side.[br]They are also equivalent in size.

Alternate Angles sit on alternating sides of the Transversal. [br]They are easily spotted if they are inside the parallel lines. [br]They can also be identified by noticing the Z shape made by the side involved with angles. [br]They are of equivalent size.

Co-Interior Angles sit inside the parallel lines, and on the SAME side of the Transversal. [br]They can also be identified by noticing the C shape made by the side involved with angles. [br]They are Supplementary.

Co-Exterior Angles sit outside the parallel lines, and on the SAME side of the Transversal. [br]They are also Supplementary.

Corresponding Angles sit on the SAME side of the Transversal, but one is inside the parallel lines, and one is outside.[br]They can be identified by the F shape made by the sides involved with the angles. [br]They are also equivalent in size.