2. Lines and Angles Terra Alta/East Preston School Geometry Unit

3. Ray Ray--part of a line that has one endpoint and goes on endlessly in the other direction.

4. Congruent Equal in size and shape.

5. Degrees The unit used to measure angles. 70

6. Line Segment A part of a line that has two endpoints.

7. Line A series of points that go endlessly in both directions.

8. Vertex The point at which two rays join together to form an angle.

9. Obtuse Angle An angle that measures more than 90 degrees.

10. Acute Angle An angle that measures less than 90 degrees.

11. Right Angle An angle that measures 90 degrees.

12. Straight Angle An angle that measures 180 degrees. (a.k.a. straight line)

13. Parallel Lines Two lines that are equal distance apart and will never intersect.

14. Perpendicular Lines Two lines that intersect to form two right angles.

15. Complimentary Angles Two angles that add up to 90 degrees.

16. Supplementary Angles Two angles that add up to 180 degrees.

17. *****Reminders****** Supplementary Straight angle Complimentary Corner

18. ***Reminders**** means angle

19. B R D E F Q S BEF DER QRS DEF BER

20. CIRCLES Radius: a line segment whose endpoints are the center of a circle and a point on the circle.

21. Diameter A line segment that passes through the center of a circle and has endpoints on the circle.

22. Arc AB A B Part of a circle

23. The End