Angle- figure formed by two rays with a common endpoint

Vertex- the common endpoint of the two rays that form an angle

Sides- The two rays that form an angle

Adjacent Angles- two angles with 1.) A common vertex 2.) A common side 3.) No common interior points

Linear Pair- two adjacent angles whose nonshared side form a pair of opposite rays.

Vertical Angles- a pair of nonadjacent angles formed by intersecting lines.

Acute- measure less than 90º

Right- equals 90º

Obtuse- greater than 90º

Straight- equals 180º (formed by opposite rays)