| A | B |
|---|
| line | A striaght set of points that extend in opposite directions without ending.,  |
| ray | Part of a line that has one endpoint and extends in one direction without ending.,  |
| endpoint | A point at the end of a line where it stops.,  |
| line segment | Part of a line between two endpoints.,  |
| parallel lines | Lines that are always the same distance apart and they do not ever meet.,  |
| intersecting lines | Lines that meet or cross each other.,  |
| perpendicular lines | Lines that meet or cross each other to form right angles.,  |
| angle | A figure made from two rays that have the same endpoint.,  |
| 1/4 turn of a circle | 90 degrees |
| 1/2 turn of a circle | 180 degrees |
| 3/4 turn of a circle | 270 degrees |
| full turn of a circle | 180 degrees |
| right angle | Made by two perpendicular rays that measure 90 degrees.,  |
| acute angle | An angle that measures greater than 0 degrees but less than 90 degrees.,  |
| obtuse angle | An angle that measures greater than 90 degrees but less than 180 degrees.,  |
| Isosceles triangle | At least two sides are the same length.,  |
| equilateral triangle | All sides are the same length.,  |
| scalene triangle | No sides are the same length.,  |
| right triangle | A triangle with one right angle.,  |
| acute triangle | A triangle has three angles that are less than 90 degrees.,  |
| obtuse triangle | A triangle that has one obtuse angle.,  |
| rectangle | A figure that has 4 right angles with opposite sides equal and parallel.,  |
| square | A figure with 4 right angles with opposite sides parallel and all the sides are equal in length.,  |
| rhombus | A figure that has 4 equal sides and opposite sides are parallel.,  |
| parallelogram | A figure that has opposite sides equal in length and parallel.,  |
| trapezoid | A figure that has exactly 1 pair of parallel sides.,  |
| radius | A line segment that connects the center or a circle to a point on the circle.,  |
| diameter | A line segment that connects two points on a circle and goes through the center of a circle.,  |
| center of a circle | The exact middle point of a circle,  |
| circle | A plane figure in which all points are the same distance from a point called the center.,  |
