| A | B |
|---|
| Point | Simply a location |
| Line | Made of points and has no thickness or width |
| Collinear | Points on the same line |
| Plane | A flat surface made of points |
| Space | A boundless, three dimensional set of all points |
| Locus | A group of points |
| Line segment | Part of a line with two endpoints |
| Precision | Depends on the smallest unit available on the measuring tool |
| Betweeness of Points | The relationship applied to points on a line |
| Relative error | Accuracy is an indication of |
| Midpoint | A point half way between the end points of a line segment |
| Segment Bisector | Any segment, line or plane that intersects a segment at its midpoint |
| Degree | The distance around a circle |
| Ray | part of a line that goes one way |
| Opposite rays | Rays on a line that go in different directions |
| Angle | Formed by two noncollinear rays that have a common endpoint |
| Sides | The rays of an angle |
| Vertex | Common endpoint of an angle |
| Interior | The inside of an angle |
| Exterior | The outside of an angle |
| Right Angle | A 90 degree angle |
| Acute Angle | An angle less than 90 degrees |
| Obtuse Angle | An angle more than 90 degrees and less than 180 degrees |
| Angle Bisector | A ray that divides an angle into two congruent (same size) angles |
| Adjacent Angles | Two angles that lie in the same plane and have a common vertex and a common side but no common interior points |
| Vertical Angles | Two nonadjacent angles formed by two intersecting opposite rays |
| Linear Pair | A pair of adjacent angles whose noncommon sides are opposite rays |
| Complementary Angles | Angles whose measures have a sum of 90 degrees |
| Perpendicular | Line that form right angles (make a T or upside down T) |
| Polygon | A closed figure whose sides are all segments |
| Concave | Any point in the interior of the polygon |
| Convex | Any point outside of the interior of a polygon |
| N-gon | A polygon with n sides |
| Regular polygon | All the angles that are congruent (the same size) in a polygon |
| Perimeter | The sum of the lengths of all sides |
