| A | B |
|---|
| A position in space | point |
| a continuous straight set of points with no end points | line |
| part of a line that has two endpoints | line segment |
| a flat surface that extends infinitely in all directions | plane |
| part of a line that has one endpoint and continues infinitely in one direction | ray |
| formed by two rays with a common endpoint called vertex | angle |
| an angle that measures 90 degrees | right angle |
| an angle that measures less than 90 degrees | acute angle |
| an angle that measures greater than 90 degrees and less than 180 | obtuse angle |
| an angle that measures 180 degrees | straight angle |
| a triangle that has one right angle | right triangle |
| a triangle that has 3 acute angles | acute triangle |
| an angle that has one obtuse angle | obtuse triangle |
| a quadrilateral has how many sides | 4 |
| a pentagon has how many sides | 5 |
| a hexagon has how many sides | 6 |
| an octagon has how many sides | 8 |
| 2 angles, the sum of which add to 90 degrees | complementary angles |
| 2 angles, the sum of which is 180 degrees | supplementary angles |
| an angle that is greater than 180 degrees and less that 360 | reflex angles |
| two angles that share a ray | adjacent angles |
| two angles that are on opposite sides of an intersection | vertical angles |
| two lines that intersect at a 90 degree angle | perpendicular lines |
| two lines that never touch | parallel lines |
| a line that intersects parallel lines | transversal |
| 2 angles in the same relative position in the intersections of a tranversal | corresponding angles |
| 2 angles that are on opposite sides of the transversal inside parallel lines | alternate interior angles |
