| A | B |
|---|
| hexagon | a polygon with six sides |
| concave polygon | a polygon in which two vertices can be connected by a line segment that is outside the polygon |
| circle | the set of all points that are the same distance from a given point |
| median | a line segment that goes from a vertex to the center of the opposite side |
| altitude | a line segment that goes from a vertex perpendicular to the opposite side |
| similar polygons | polygons whose corresponding sides are proportional |
| rhombus | a parallelogram that has four congruent sides |
| trapezoid | a quadrilateral that has exactly two parallel sides |
| convex polygon | a polygon in which any two nonadjacent vertices can be connected by a line segment inside the polygon |
| straight angle | an angle whose measure is 180 degrees |
| complementary angles | two angles the sum of whose measures is 90 degrees |
| supplementary angles | two angles the sum of whose measures is 180 degrees |
| regular polygon | a polygon with all sides congruent |
| equiangular triangle | a triangle with all angles of equal measure |
| parallelogram | a quadrilateral in which opposite sides are parallel |
| centroid | the point of concurrency of the three medians of the triangles |
| circumference | the distance around a circle |
| rectangle | a parallelogram with one right angle |
| pentagon | a polygon with five sides |
| decagon | a polygon with ten sides |
