1. Geometry Basic Vocabulary

2. Point • A point marks an exact location in space. • It has no size. It is infinitely small. • Use a capital print letter to name a point.

3. Line • A line is an endless straight path. • It is the infinitely straight arrangement of points. • Use any two points on the line to name the line. AG or GA or JG or AJ… J

4. Line Segment • A line segment is part of a line between two endpoints. • Use the two endpoints to name the line segment. AG or GA

5. Ray • A ray is part of a line that has one endpoint and goes on forever in one direction. • Use the endpoint and one other point on the ray to name a ray. Endpoint first. ALWAYS! Ray GA Or GA

6. Plane • A plane is an endless flat surface. • Use three points that are not on a line to name the plane or the capital cursive letter in the corner. Plane GFH Or Plane B B

7. Angle • An angle is formed by two rays with the same endpoint. • An angle can be named by three letters – a point from each side and the vertex as the middle letter. • If there are no other angles at the vertex, it can also be named by a single letter, its vertex. <GFH or <F

8. Right Angle • A right angle measures 90° blue box indicates a right angle

9. Acute Angle • An acute angle is greater than 0 and less than 90° 60°

10. Obtuse Angle • An obtuse angle is greater than 90 and less than 180° 140°

11. Straight Angle • A straight angle measures 180°. • Also known as a line.

12. Intersecting Lines • Intersecting lines are lines that cross at one point.

13. Parallel Lines • Parallel lines are lines in a plane that never intersect and are the same distance apart at every point.

14. Perpendicular Lines • Perpendicular lines are lines that intersect to form four right angles.