Lesson 1 1 Points Lines and Planes Geometry

Lesson 1. 1: Points, Lines, and Planes Geometry CP Mrs. Mongold

Chapter 1 Foldable Flap 1 Point P Line A B A capital letter A point has neither shape or size A line segment with an arrow at each end Two capital letters representing points on the line There is exactly one line through any two points A capital script letter, or by the letters naming three noncollinear points There is exactly one plane through any three noncollinear points A shaded B slanted 4 sided figure Plane A D As a dot C

Undefined Term • Things that can only be described using examples and descriptions – Examples: Points, Lines, and Planes

Definitions • Point: A location • Line: An object made of points that has no width or thickness • Plane: a flat surface made up of points • Collinear: points that are on the same line • Coplanar: points that lie on the same plane

Examples of Points • • The tip of a pen or pencil The head of a pin A hole in a piece of paper Where the lines on a piece of paper intersect • Can you think of some examples?

Examples of Lines • • The lines on notebook paper The metal strips on the ceiling The paint on the highway The mortar between cinderblocks • Can you think of some lines?

Examples of Planes • The top of a table or desk • A window pane • A sheet of paper

Name three collinear points

Answers 1. D, H, A 2. D, G, F

Name three coplanar points

Answers • • • 1. D, H, A 2. D, H, C 3. H, A, C 4. D, G, F 5. D, F, C 6. G, F, C 7. A, B, C 8. A, B, F 9. A, C, f 10. B, C, F

Name the intersection of • Plane DHC and Plane P • Plane ACF and Plane DFC • Line CF and Line DA • Line CD and Plane P

Answers • • Line AC Line FC Will never intersect Point C

3 -2 -1 Ticket Out The Door • 3 real life examples of points not already named in class • 2 real life examples of lines not already named in class • 1 real life example of a plane not already named in class