2. Point a zero-dimensional figure; while usually left undefined, has four main representations - the dot, the node, the location, and the ordered pair of numbers.
3. Line (Segment) A straight line which links two points without extending beyond them.
4. Plane A two-dimensional group of points that goes on infinitely in all directions; made up of infinite lines.
5. Angle A shape, formed by two lines or rays diverging from a common point (the vertex).
6. Perpendicular Lines A line is perpendicular to another if it meets or crosses it at right angles (90°).
7. Parallel Lines Lines are parallel if they lie in the same plane, and are the same distance apart over their entire length.
8. Triangle A closed figure consisting of three line segments linked end-to-end. A 3-sided polygon.
9. Right Triangle A triangle where one of its interior angles is a right angle (90 degrees).
10. Pentagon A number of coplanar line segments, each connected end to end to form a closed shape.