| A | B |
|---|
| right angle | A 90 degree angle. It makes a corner like on the edge of your paper. |
| equilateral triangle | A triangle with all sides equal. |
| scalene triangle | A triangle having three unequal sides and angles. |
| vertex | A point where two sides meet. |
| right triangle | A triangle with one angle equal to a right angle. |
| pentagon | A polygon with 5 sides and 5 angles. |
| square | A rectangle having all four sides of equal length. It has 4 right angles. |
| intersecting lines | Lines that cross each other. |
| radius | A straight line extending from the center of a circle to the outside edge. |
| line segment | One part of a line. It has two endpoints. |
| line | A straight path that goes on without end in two directions. |
| point | A position in space. |
| rectangle | A quadrilateral with opposite sides parallel. It has 4 right angles. |
| circle | A closed plane figure. |
| hexagon | A six sided figure |
| ray | A part of a line. It has one endpoint. It goes on without end in one direction. |
| angle | It is formed by two rays with the same endpoint. |
| plane figure | It is a flat figure. It can be closed or not closed. |
| polygon | A closed plane figure that is made up of three or more segments. It has the same number of sides and angles. |
| quadrilateral | A polygon with 4 sides and 4 angles. |
| parallel | Lines that are always the same distance apart. |
| parallelogram | It has 4 sides, 4 angles, and the opposite sides are parallel. |
| isoceles triangle | An triangle that has two sides of equal length. |
| congruent | Plane figures with the same size and shape. |
| symmetry | A plane figure that has this can be folded along a line so that the two parts match exactly. |
| line of symmetry | The line upon which a plane figure can be folded to make two parts match exactly. |
| perimeter | The distance around a figure. You can add all the distance around the outside to find this. (It is like a fence around the outside edges.) |
| area | The number of square units in a region. (It covers the figure like a rug.) |
| solid figure | It is 3-dimensional, not flat like a plane figure. (You can hold it.) |
| volume | The number of cubic units that fit inside a solid figure. |
