Warm Up Problem of the Day Lesson Presentation Lesson Quizzes

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

Problem of the Day Remove 4 of the segments to leave 5 equal squares.

Learn to identify and describe geometric figures.

Vocabulary point line plane ray line segment congruent

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

Has no thickness and extends forever. plane QRS Use three points A plane is a Flat surface that Has no thickness and extends forever. plane QRS Use three points in any order, not on the same line, to name a plane. Q R S A coordinate plane is an example of a plane. Helpful Hint

Additional 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 two points on a line to name the line. B. two lines DE, DF Choose any three points, not on the same line, in any order. C. a plane plane DEF

Identify the figures in the diagram. Check It Out: Example 1 Identify the figures in the diagram. G H I F A. four points H, G, I, and F 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, in any order. C. a plane plane IGF

A ray is a part of a line. It has one endpoint and extends forever one direction. GH Name the endpoint first when naming a ray. H G A line segment is part of a line. or a ray that extends from one endpoint to another. LM, or ML Use the endpoints to name a line segment. L M

Additional Example 2: Identifying Line Segments and Rays Identify the figures in the diagram. M N O 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

Check It Out: Example 2 Identify the figures in the diagram. D C A. three rays Name the endpoint of a ray first. B A BC, CA, BD B. three line segments BA, CA, BD Use the endpoints in any order to name a segment.

Figures are congruent if they have the same shape and size 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 triangle below, line segments AB and BC are congruent.

Additional Example 3: Identifying Congruent Line Segments Identify the line segments that are congruent in the figure. AB CD One tick mark AC BD Two tick marks BF DF EC AE Three tick marks The symbol means “is congruent to.” Reading Math

Identify the line segments that are congruent in the figure. Check It Out: Example 3 Identify the line segments that are congruent in the figure. A B C D E AB AC One tick mark BC DE Two tick marks BD CE Three tick marks

Lesson Quizzes Standard Lesson Quiz Lesson Quiz for Student Response Systems

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

Lesson Quiz for Student Response Systems 1. Identify the lines in the diagram. A. B. AB, AE C. D.

Lesson Quiz for Student Response Systems 2. Identify a plane in the diagram. A. plane AFD B. plane EFC C. plane ABC D. plane BGF

Lesson Quiz for Student Response Systems 3. Identify three rays in the diagram. A. B. C. D.

Lesson Quiz for Student Response Systems 4. Identify the line segments that are congruent in the figure. A. B. C. D.