| A | B |
|---|
| polygon | a closed figure with sides that are line segments. |
| vertex | the point were two rays meet. the point of intersection of two sides of a polygon. |
| quadrilateral | a polygon with 4 sides and 4 vertices. |
| point | an exact location in space. |
| line | a collection of points that go on and on in both directions. |
| line segment | is a part of a line with two endpoints. |
| ray | is part of a line that has one endpoint and continues on and on in one direction. |
| intersecting lines | lines that pass through the same point. |
| parallel lines | lines that runs side by side and never intersect. |
| perpendicular lines | lines that intersect to form right angles. |
| triangle | a polygon with 3 sides and 3 vertices. |
| pentagon | a polygon with 5 sides and 5 vertices. |
| hexagon | a polygon with 6 sides and 6 vertices. |
| octagon | a polygon with 8 sides and 8 vertices. |
| decagon | a polygon with 10 sides and 10 vertices. |
| angle | two rays with a common endpoint |
| right angle | the angle of a square measuring 90 degrees. |
| obtuse angle | an angle greater than a right angle measuring greater than 90 degrees. |
| acute angle | an angle smaller than a right angle measuring less than 90 degrees. |
| straight angle | an angle measuring 180 degrees. |
| circle | a closed plane figure which all points are the same distance from a point called the center. |
| radius | a line segment with one endpoint on the circle and the other endpoint at the center. |
| diameter | a line segment that passes through the center of a circle and has both endpoints on the circle. |
| chord | a line segment that has endpoints on the rim but does not pass through the center. |
| circumference | is the distance around a circle. |
| congruent | figures that have the same size and shape. |
| similar | figures with the same shape but not the same size. |
| symmetry | a figure can be folded along a line and its two parts match exactly. |
| perimeter | distance around a polygon. To find it add up the length of all the sides. |
| area | the number of square units needed to cover the region. Formula: length x width |
| volume | the number of cubic units that fit inside a space figure. Formula: length x width x height. |
| trapezoid | a quadrilateral with only one pair of parallel sides. |
| rhombus | a quadrilateral in which opposite sides are parallel and all sides are the same length. |
| parallelogram | a quadrilateral in which opposite sides are parallel. |
| rectangle | a quadrilateral with four right angles. |
| square | a quadrilateral with four right angles and all the sides the same length. |
