Term | Definition |
Collinear points | points that lie on the same line. |
Coplanar | points and lines lie in the same plane. |
Intersection | the set of points the figures have in common. |
Line | a straight path that extends in two opposite directions without end and has no thickness; contains infinitely many points. |
Opposite rays | two rays that share the same endpoint and form a line. |
Plane | represented by a flat surface that extends without end and has
no thickness; contains infinitely many lines. |
Point | indicates a location and has no size. |
Postulate | an accepted statement of fact. |
Ray | part of a line that consists of one endpoint and all points of the line on one side of the endpoint. |
Segment | part of a line that consists of two endpoints and all points between them. |
Congruent segments | Two segments that have the same length. |
Coordinate | the real number that corresponds to the location of a point. |
Distance | the absolute value of the difference of two point's coordinates. |
Midpoint | the point that divides a segment into two congruent segments. |
Segment bisector | a point, a line, a ray, or another segment that intersects a segment at its midpoint. |
Acute angle | an angle whose measure is between 0 and 90. |
Angle | formed by two rays with the same endpoint. |
Congruent angles | angles with the same measure. |
Obtuse angle | an angle whose measure is between 90 and 180. |
Right angle – A right angle is | an angle whose measure is 90. |
Straight angle | an angle whose measure is 180. |
Vertex of an angle | the common endpoint of the two rays that form the angle. |