| A | B |
|---|
| line (straight line) | infinite number of points extending without end in two directions |
| line segment | part of a line that lies between two definite points |
| parallel lines | Lines that do not meet regardless of how far they are extended. They are the same distance apart at all points. |
| perpendicular lines | Two lines that meet or intersect and form a right angle. |
| oblique lines | Lines that meet or intersect at an angle other than 90%. They are not parallel or perpendicular. |
| angle | Two lines or rays that meet a point called a vertex. Two rays with a common endpoint. |
| vertex | The point were two lines meet and form an angle. |
| acute angle | An angle that measures less than 90 degrees. |
| right angle | An angle that measures 90 degrees. |
| obtuse angle | An angle that is greater than 90 degrees but less than 180 degrees. |
| reflex angle | An angle that measures greater than 180 degress, but less than 360 degrees. |
| adjacent angles | Two angles that have a common side and a common vertex. |
| transversal | A line that intersects two or more lines. |
| alternate interior angles | Pairs of angles between the lines intersected by a transveral and on opposite sides of the transversal. They have different vertices, but are equal. |
| corresponding angles | Pairs of angles one interior and one exterior with both angles on the same side of the transversal. These angles are equal. |
| alternate exterior angles | Pairs of angles outside of the lines intersected by a transversal and on opposite sides of the transversal. These angles are equal. |
| complementary angles | Two angles whose sum is 90 degrees. |
| supplementary angles | Two angles whose sum is 180 degrees. |
| straight angle | An angle that measures 180 degrees. A straight angle is a straight line. |
