| A | B |
|---|
| polygon | a closed figure formed by straight line segments |
| quadrilateral | a polygon with 4 sides |
| parallelogram | a quadrilateral with two pairs of parallel sides, and no right angles |
| rectangle | a quadrilateral with 4 right angles and two pairs of equal and parallel sides |
| square | a quadrilateral with 4 right angles and 4 equal sides |
| rhombus | a quadrilateral with all sides the equal and no right angles |
| trapezoid | a quadrilateral with only one pair of parallel sides |
| octagon | an eight sided polygon |
| triangle | a polygon with three sides |
| equilateral triangle | a polygon with 3 equal sides and angles (all angles are 60 degrees) |
| isosceles triangle | a triangle with at least 2 sides the same length |
| scalene triangle | a triangle with no sides the same length |
| vertex | the point that the two rays of an angle have in common (corner) |
| right angle | an angle that measures 90 degrees |
| acute angle | an angle that measures less than 90 degrees |
| obtuse angle | an angle that measures more than 90 degrees |
| point | an exact location on a line or line segment |
| line | a straight path that goes on forever in both directions |
| line segment | part of a line that has a beginning and ending point |
| parallel lines | two lines that will never intersect |
| intersecting lines | two lines that cross each other |
| line of symmetry | a line a figure can be folded on so that the 2 folds are exactly the same |
| congruent | having exactly the same measure angles and sides |
| similar | figures with the same shape, but not the same size (however corresponding sides are in proportion) |
