| A | B |
|---|
| point | a location. |
| line | is made up of points and has no thickness or width. |
| collinear | are points on the same line. |
| plane | a flat surface made up of points. |
| coplanar | are points that lie on the same plane. |
| undefined terms | point, line, and plane. |
| space | a boundless, three-dimensional set of all points. |
| locus | a way to describe a group of points. |
| line segment | can be measured because it has two endpoints. |
| precision | depends on the smallest unit available on the measuring tool. |
| congruent | when segments have the same measure. |
| constructions | are methods of creating geometric figures without the benefit of measuring tools. |
| absolute error | the absolute value of the difference between the actual measure of an object and the allowable measure. |
| relative error | is the ratio of the absolute error to the actual measure. |
| midpoint | the point halfway between the endpoints of a segment. |
| segment bisector | any segment, line, or plane that intersects a segment at its midpoint. |
| degree | a unit that resulted from dividing the circumference, or the distance around a circle into 360 parts. |
| ray | part of a line. |
| angle | formed by two noncollinear rays that have a common endpoint. |
| vertex | common endpoint of an angle. |
| interior | inside of an angle. |
| exterior | outside of an angle. |
| right angle | 90 degrees. |
| acute angle | less that 90 degrees. |
| obtuse angle | greater than 90 degrees. |
| angle bisector | a ray that divides an angle into two congruent angles. |
| adjacent angles | two angles that lie in the same plane, have a common vertex, and a common side, but no common interior points. |
| vertical angles | are two nonadjacent angles formed by two intersecting lines. |
| linear pair | a pair of adjacent angles whose noncommon sides are opposite rays. |
| complementary angles | two angles whose measures have a sum of 90 degrees. |
| supplementary angles | two angles whose measures have a sum of 180 degrees. |
| perpendicular | lines that form right angles. |
| polygon | a closed figure whose sides are all segments. |
| convex polygon | no points of the lines are in the interior. |
| concave polygon | some of the lines pass through the interior. |
| regular polygon | a convex polygon in which all the sides are congruent and all the angles are congruent. |
| perimeter | the sum of the lengths of a polygon's sides, which are segments. |
