| A | B |
|---|
| center | dot in the middle of a circle |
| diameter | line segment that passes thru the center of a circle & has endpoints on the circle |
| equilateral triangle | 3 sides that are the same length |
| isosceles triangle | at least 2 sides are the same length |
| scalene triangle | no sides are the same length |
| congruent figures | same size & shape |
| polygon | a closed plane figure formed by 3 or more line segments that meet only at their endpoints |
| regular polygon | a polygon whose sides are the same length & angles are all equal |
| tesselation | an arrangement of repeated, closed shapes that cover a surface so that no shapes overlap; with no gaps between shapes |
| regular tessellation | consisting of congruent copies of one regular polygon |
| vertical angle | 2 angles that are opposite each other |
| adjacent angle | 2 angles next to each other |
| 360` | measure of a circle |
| 180 | measure of a straight line |
| acute angle | measure of angle is more than 0 & less than 90 |
| obtuse angle | measure of angle is greater than 90 & less than 180 |
| right angle | measure of angle is 90 |
| straight angle | measures 180 |
| reflex angle | measure is bigger than 180 & less than 360 |
| radius | line segment from the center of the circle to any point on the circle |
