| A | B |
|---|
| 3 sided figure | triangle |
| 4 sided figure | quadrilateral |
| 5 sided figure | pentagon |
| 6 sided figure | hexagon |
| 7 sided figure | heptagon |
| 8 sided figure | octagon |
| 9 sided figure | nonagon |
| 10 sided figure | decagon |
| 12 sided figure | dodecagon |
| the mirror image of a figure across a line of symmetry | reflection |
| simple closed figure formed by three or more sides | polygon |
| any polygon with all sides congruent and all angles congruent | regular polygon |
| lines that never meet | parallel |
| all sides and all angles of the triangle are congruent | equilateral triangle |
| figures with the same shape and angles but different sizes | similar figures |
| figures with the same size and shape | congruent figures |
| angles between 0 and 90 degrees | acute |
| angles between 90 and 180 degrees | obtuse |
| square, rectangle, parallelogram, and trapezoid | different kinds of quadrilaterals |
| equal or the same | congruent |
