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. B Plane GFH Or Plane 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.