| A | B |
|---|
| Angle | Two rays that meet at a common endpoint |
| Acute Angle | An angle with a measure less than 90 degrees |
| Circle | The set of all points that lie the |
| Congruent | Same size, same shape |
| Hexagon | A polygon with 6 sides, 6 angles, and 6 vertices |
| Line | A set of points that form a straight path that goes in opposite directions without ending |
| Line Segment | Part of a line between two endpoints |
| Obtuse Angle | An angle whose measure is greater than 90 degrees |
| Octagon | A polygon with 8 sides, 8 angles, and 8 vertices |
| Parallel Lines | Lines that lie in the same plane, never intersect, and are the same distance apart |
| Parallelogram | Four-sided (quadrilateral) polygon with opposite sides parallel and opposite sides congruent |
| Perpendicular Lines | Lines that intersect at right angles (90 degrees) to each other |
| Pentagon | A polygon with 5 sides, 5 angles, and 5 vertices |
| Plane | A flat surface that goes on forever in all directions |
| Point | An exact location in space, represented by a dot |
| Polygon | A closed figure made by joining line segments, where each line segment intersects exactly two others only at the endpoints |
| Quadrilateral | Any four-sided polygon |
| Ray | Part of a line that has one endpoint and continues without end in one direction |
| Rectangle | Four-sided polygon (quadrilateral) with 4 right (90 degrees) angles, adjacent sides perpendicular, opposite sides congruent, and opposite sides parallel |
| Right Angle | An angle that measures 90 degrees; lines that are at a right angle to each other are perpendicular |
| Rhombus | Four-sided polygon (quadrilateral) having all four sides congruent and opposite sides parallel |
| Square | Four-sided polygon (quadrilateral) with all sides congruent, opposite sides parallel, 4 right (90 degrees) angles, and adjacent sides perpendicular |
| Trapezoid | Four-sided polygon (quadrilateral) with exactly one pair of parallel sides |
| Triangle | A polygon with 3 sides, 3 angles, 3 vertices |
| Two-Dimensional | A figure that has two basic units of measurement (usually length and width) |
| Vertex (plural - vertices) | The point (corner) of intersection of two edges in a two-dimensional figure |
