8-1 Building Blocks of Geometry Course 2 Warm Up Warm Up Lesson Presentation Lesson Presentation Problem of the Day Problem of the Day

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 Course Building Blocks of Geometry

Problem of the Day Remove 4 of the segments to leave 5 equal squares. Course Building Blocks of Geometry

Learn to identify and describe the building blocks of geometry. Course Building Blocks of Geometry

Vocabulary point line ray line segment plane congruent Insert Lesson Title Here Course Building Blocks of Geometry

A point is an exact location in space. 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. A line is a straight path that extends without end in opposite directions. A number line is an example of a line. Helpful Hint XY, or YX Use two points on the line to name a line. X Y Course Building Blocks of Geometry

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. A coordinate plane is an example of a plane. Helpful Hint Q R S Course Building Blocks of Geometry

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

Check It Out: Example 1 Insert Lesson Title Here H I A. four points B. two lines C. a plane H, G, I, and F IH, HF plane IGF Identify the figures in the diagram. G Choose any two points on a line to name the line. Choose any three points, not on the same line, in any order. F Course Building Blocks of Geometry

A ray is a part of a line. It has one endpoint and extends without end in one direction. GH Name the endpoint first when naming a ray. 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 H G Course Building Blocks of Geometry

Identify the figures in the diagram. Additional Example 2: Identifying Line Segments and Rays M N O A. three rays B. two line segments MN, NM, MO MN, MO Name the endpoint of a ray first. Use the endpoints in any order to name a segment. Course Building Blocks of Geometry

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

Figures are congruent if they have the same shape and size. If you place one on top of the other, they match exactly. 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. A C B 20 m 16 m Course Building Blocks of Geometry

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

Check It Out: Example 3 Identify the line segments that are congruent in the figure. Insert Lesson Title Here AB AC BC DE BD CE One tick mark Two tick marks Three tick marks A B C D E Course Building Blocks of Geometry

Lesson Quiz Insert Lesson Title Here Identify the figures in the diagram. 1. lines 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. AD, BE, CF Course Building Blocks of Geometry AG GD, GB GE