Warm Up

1. Preview Warm Up California Standards Lesson Presentation

2. Warm Up What geometry term might you associate with each object? 1.one edge of a cardboard box 2. the floor 3. the tip of a pen line segment or line plane or rectangle point

3. California Standards Preparation for MG2.1 Identify angles as vertical, adjacent, complementary, or supplementary and provide descriptions of these terms.

4. Objective: You will learn how to (YWLHT) identify and describe geometric figures.

5. Vocabulary point line plane ray line segment congruent

6. XY, YX, or l X Y Use two points on the line or a lowercase letter to name a line. A pointis an exact location. It is usually represented as a dot, but it has no size at all. point A Use a capital letter to name a point. • A l A lineis a straight path that extends without end in opposite directions.

7. Q S R A plane is a perfectly flat surface that extends infinitely in all directions. plane QRS Use three points in any order, not on the same line, to name a plane.

8. Example 1: Identifying Points, Lines, and Planes Identify the figures in the diagram. D E F A. three points D, E, and F Choose any three points. Choose any two points on a line to name the line. B. two lines DE, DF Choose any three points, not on the same line to name a plane. plane DEF C. a plane

9. Check It Out! Example 2 Identify the figures in the diagram. G H I F A. four points H, G, I, and F Choose any four points. Choose any two points on a line to name the line. B. two lines IH, HF Choose any three points, not on the same line to name a plane. C. a plane plane IGF

10. GH Name the endpoint first when naming a ray. G H LM or ML Use the endpoints to name a line segment. L M A ray is a part of a line. It has one endpoint and extends without end in one direction. A line segmentis part of a line or a ray that extends from one endpoint to another.

11. M N O Example 3: Identifying Line Segments and Rays Identify the figures in the diagram. A. three rays Name the endpoint of a ray first. MN, NM, MO B. two line segments Use the endpoints in any order to name a segment. MN, MO

12. D C B A Check It Out! Example 4 Identify the figures in the diagram. A. three rays Name the endpoint of a ray first. BC, CA, BD B. three line segments Use the endpoints in any order to name a segment. BA, CA, BD

13. Figures are congruent if they have the same shape and size. Line segments are congruent if they have the same length. You can use tick marks to indicate congruent line segments. In the illustration below, line segments AB and BC are congruent.

14. AB CD ACBD BF DF EC AE Reading Math The symbol means “is congruent to.” Example 5: Identifying Congruent Line Segments Identify the line segments that are congruent in the figure. One tick mark Two tick marks Three tick marks

15. A AB AC BCDE B C BD CE E D Check It Out! Example 6 Identify the line segments that are congruent in the figure. One tick mark Two tick marks Three tick marks

16. Home Learning On-Line Tutoring Geo-match-try Geo-fit Geo-Terms Geo-Vocab Shape Quiz Angle Tangle

17. AD, BE, CF Possible answer: GA, GB, GC Possible answer: AG, AD, DG, BG AG GD, GB GE Lesson Quiz Identify the figures in the diagram. 1. lines 2. plane Possible answer: plane ABG 3. three rays 4. four line segments 5. Identify the line segments that are congruent in the figure.