| A | B |
|---|
| line | a set of points that extends without end iin two opposite directions |
| point | a position in space represented by a dot |
| ray | a part of a line that has one endpoint and extends without end in one directions |
| segment | a part of a linet that consists of two endpoints and all the points between them |
| plane | a flat surface that extends without end in all directions |
| intersecting lines | lines in a plane that meet at a point |
| parallel lines | lines in the same plane that never meet |
| perpendicular lines | two lines on the same plane that meet at a right angle |
| angle | a figure formed by two rays with the same endpoint |
| vertex | the endpoint of the rays that form the angle |
| right angle | an angle whose measure is exactly 90 degrees |
| acute angle | an angle whose measure is less than 90 degrees |
| obtuse angle | an angle whose measure is between 90 and 180 degrees |
| straight angle | an angle whose measure is exactly 180 degrees |
| vertical angles | when two angles intersect, the angles are opposite each other |
| complimentary angles | two angles whose measures have a sum of 90 degrees |
| supplementary angles | two angles whose measures have a sum of 180 degrees |
| equilateral triangle | a triangle whose three sides have the same length |
| scalene triangle | a triangle who has three sides of different lenghts |
| isosceles triangle | a triangle with at least two sides of the same length |
| quadrilateral | a plane figure formed by 4 segments |
| parallelogram | a quadrilateral with two pairs of parallel sides |
| rectangle | parallelogram with four right angles |
| rhombus | parallelogram with four sides of equal length |
| square | parallelogram with four right angles and four sides of equal length |
| polygon | a closed plane figure that is formed by three or more segments called sides |
| pentagon | polygon with five sides |
| hexagon | polygon with six sides |
| octagon | polygon with eight sides |
| congruent figures | figures with the same size and shape |
| similar figures | figures with same shape but not the same size |
| corresponding parts | matching sides and angles of two figures |
| line of symetry | if a line can be drawn that divides the figure into two congruent parts that are mirror images of each other |
| regular polygon | a polygon with equal side lengths and equal angle measures |
| diagonal | a segment other than a side that connects two vertices of a polygon |
