| A | B |
|---|
| polygon | a closed figure made of line segments that meet at their endpoints |
| regular polygon | a polygon with all congruent sides and angles |
| diagonal | a segment that joins any 2 non-consecutive veritices |
| perimeter | the sum of the lengths of the sides of a polygon |
| quadrilateral | a 4-sided polygon |
| pentagon | a 5-sided polygon |
| hexagon | a 6-sided polygon |
| octagon | a 8-sided polygon |
| decagon | a 10-sided polygon |
| parallelogram | a quadrilateral with 2 pair of parallel sides |
| trapezoid | a quadrilateral with one pair of parallel sides |
| rectangle | a parallelogram with 4 congruent angles |
| rhombus | a parallelogram with 4 congruent sides |
| square | a parallelogram with 4 congruent sides and 4 congruent angles |
| circle | a set of points in a plane at a given distance from a given point |
| radius | a segment joining the center to a point on a circle |
| chord | a segment joining 2 points on a circle |
| diameter | a chord passing through the center of a circle |
| semicircle | half a circle |
| arc | part of a circle |
| circumference | the distance around a circle |
| pi | the ratio of circumference to diameter |
| inscribed polygon | a polygon whose vertices are all on the circle |
| tangent | a line that touches the circle at only one point |
