| A | B |
|---|
| Point | A location in space with no dimension. |
| Plane | A flat surface with no thickness that extends forever. |
| Ray | Begins with an endpoint and extends in one directions forever. |
| Segment | Part of a line with two endpoints and everything between. |
| Endpoint | The points at the ends of a segment of the beginning of a ray. |
| Angle | Formed by two rays meeting a common vertex. |
Acute Angle,  | An angle less than 90 degrees. |
Obtuse Angle,  | An angle greater than 90 and less than 180 degrees. |
| Right Angle | An angle exactly 90 degrees. |
| Straight Angle | An angle exactly 180 degrees ~ a straight line. |
| Reflex Angle | An angle greater than 180 and less than 360 degrees. |
| Collinear | Three or more points on the same line. |
| Coplanar | On the same plane. |
| Adjacent Angles | Angles that share a side and a vertex ~ "Next to" |
| Vertical Angles | Angles formed by intersecting lines. "Across from" Always congruent. |
Complementary Angles,  | Adjacent angles whose sum is 90 degrees. |
Supplementary Angles,  | Adjacent angles whose sum is 180 degrees. |
Quadrilateral,  | A polygon with 4 sides. |
| Triangle | A polygon with 3 sides. |
Pentagon,  | A polygon with 5 sides. |
Hexagon,  | A polygon with 6 sides. |
Octagon,  | A polygon with 8 sides. |
| Heptagon | A polygon with 7 sides. |
| Eneagon | A polygon with 9 sides. |
Decagon,  | A polygon with 10 sides. |
Trapezoid,  | A quadrilateral with one pair of opposite parallel sides. |
Parallelogram,  | A quadrilateral with two pairs of opposite parallel sides. Opposite side and angles are congruent. |
Rhombus,  | A quadrilateral with two pairs of opposite parallel sides. All side lengths are congruent. |
Rectangle,  | A quadrilateral with two pairs of opposite parallel sides and 4 90 degree angles. |
Square,  | A quadrilateral with two pairs of opposite parallel sides, 4 congruent angles and 4 90 degree angles. |
Vertex,  | The corners of polygons. The place the two sides of angles meet. |
| The place where 2 lines intersect | Point |
| The place where 2 planes intersect | Line |
Right Triangle,  | A triangle with one 90 degree angle |
| Acute Triangle, | A triangle with three angles less than 90 degrees |
| Obtuse Triangle, | A triangle with one angle greater than 90 degrees |
| Equilateral Triangle | A triangle with 3 equal sides and 3 60 degree angles. |
Isosceles Triangle,  | A triangle with 2 equal sides and 2 equal angles. |
Scalene Triangle,  | A triangle with no equal sides and no equal angles. |
| Skew | Lines that never intersect and are not parallel. |
Regular Polygon,  | An equilateral & equiangular polygon |
| Parallel | Lines, segments, rays, or planes that never intersect and are always the same distance apart. |
| Perpendicular | Lines, segments, rays or planes that meet or intersect forming 90 degree angles. |
| Intersecting | Lines, segments, rays or planes that meet or intersect. |
| Equilateral | All sides are congruent. |
| Equiangular | All angles are congruent. |
| Congruent | Same Size, Same Shape, Equal. |
| Line | A never ending row of points extending in both directions forever. |
| Find the value of x, | 60 degrees |
Find the value of x,  | 30 degrees |
| Find the value of x, | 150 degrees |
Find the value of x,  | 150 degrees |
corresponding angles,  | Angles in a figure that "match". Corresponding Angles are congruent |
