| A | B |
|---|
| Acute angle | Angle with measure less than 90 degrees |
| Adjacent angles | angles with a common vertex, common side and no interior points in common |
| Angle | Union of two rays with common end point that are non-collinear |
| Bisect | To cut in two equal parts |
| Complimentary angles | Two angles with a sum of 90 degrees |
| Congruent | Two figures with equal measure |
| Line | A series of points that extend in opposite directions without end |
| Midpoint | Point that divides a segment into two equal parts |
| Obtuse angle | Angle with measure greater than 90 degrees |
| Parallel lines | Lines in the same plane that don't intersect |
| Perpendicular lines | Two lines that intersect to form right angles |
| Plane | A flat surface with no thickness that extends indefinitely in all directions |
| Point | A position in space with no size |
| Ray | A part of a line that is bounded by one endpoint |
| Right angle | Angle with measure of 90 degrees |
| Segment | A part of a line that is bounded by two endpoints |
| Skew lines | Non-coplaner lines that do not intersect |
| Supplementary angles | Two angles with a sum of 180 degrees |
| Vertex | The common endpoint of two rays or segments |
| Vertical angles | Two non-adjacent angles formed when two lines intersect |
