Adjacent angles- two angles that are directly next to each other and share a side.

Supplementary angle- two angles whose measures sum to 180 degrees (A half circle, straight angle)

Complementary angle- two angles with a sum of 90 degrees (They form a right angle)

Vertical Angle- (AKA opposite angles) vertical angles are congruent (equal in size to one another)

Parallel lines- lines that if extended indefinilely will never touch

Transversal- a line that cuts across lines

Parallel lines intersected by a transversal- lines that are cut by a transversal to form several pairs

Corrosponding angle- appear at different intersecting point but in the same position. corresponding angles are congruent to one anoother

Alternate Interior angles- angles formed inside parallel lines but on opposite sides of the transversal that are congruent

Alternate exterior angles- angles on the exterior of parallel lines buttom the opposite sides of the transversal that are congruent