| A | B |
|---|
| Acute angle | Measure is less than 90 |
| Adjacent angles | Share a vertex and common side without overlapping |
| Angle | Two rays with a common endpoint |
| Angle bisector | Ray that cuts an angle into two congruent angles |
| Collinear | On the same line |
| Coplanar | In the same plane |
| Complementary angles | Sum of measures is 90 |
| Congruent | The same size and shape |
| Coordinate | A number that corresponds to a point |
| Linear pair | Two angles that are adjacent and supplementary |
| Midpoint | The point on a line that is equidistant from the endpoints |
| Obtuse angle | Measure is between 90 and 180 |
| Perpendicular | Forming a right angle |
| Right angle | Measure is exactly 90 |
| Straight angle | Measure is exactly 180 |
| Conjunction | The combining of two statements with "and" |
| Disjunction | The combining of two statements with "or" |
| Intersection | The set of points common to two or more figures |
| Distance | The difference between the coordinates of two points |
| Line | A one-dimensional figure with no endpoints |
| Point | A location in space with no dimensions |
| Plane | A two-dimensional surface |
| Postulate | A statement that is accepted without being proven |
| Theorem | A statement that has been proven |
| Space | The set of all points |
| Proof | A logical series of statements leading to a conclusion |
| Ray | A set of collinear points with only one endpoint |
| Segment | Two endpoints and all the collinear points between them |
| Supplementary angles | Sum of angle measures is 180 |
| Vertex | The common endpoint of the rays that make up an angle |
