1. Mrs. McConaughyGeometry1 Points, Lines, and Planes During this lesson, you will:  Define and illustrate basic geometric terms  Illustrate basic postulates of geometry

2. Mrs. McConaughyGeometry2 Part I: Basic Terms of Geometry

3. Mrs. McConaughyGeometry3 In geometry, point, line, and plane are undefined terms. It is important, however, to have general descriptions of their meanings. Remember: Points, lines, and planes are undefined terms. They are the building blocks of geometry.

4. Mrs. McConaughyGeometry4 TermDescription/ Real-Life Model DiagramSymbol/ Read: Point Line Plane. A location; has no size Ex. _______ A B C Set of points extending infinitely in both directions x AM Read: “line AM” Read: “line x ” H D.O. G. A, B, C Read: “point __” Read: “Plane H ” Read: “Plane DOG” Flat surface which extends infinitely in all directions T E A M

5. Mrs. McConaughyGeometry5 Vocabulary _____________________ __________________________________ __________________________________ ________ Collinear points are two or more points which lie on the same line. coplanar. Points and lines which lie on the same plane are Collinear points Remember: Points, lines, and planes are _____________ They are the building blocks of geometry. undefined terms.

6. Mrs. McConaughyGeometry6 Identifying Collinear Points Given the following sets of points, determine if they are collinear or non- collinear. If they are collinear, name the line on which they lie. Be sure to name each line at least two (2) ways. a.W, O, M b.W, E, M c. W, N, E W E m n l N M O Noncollinear Collinear Name line l in three other ways.

7. Mrs. McConaughyGeometry7 Checking for Understanding 1. Each surface of the ice cube represents part of a plane. Name the plane represented by the front of the ice cube. 2. List three different names for the plane represented by the top of the ice cube. A B C H G F E

8. Mrs. McConaughyGeometry8 Part II: Basic Postulates of Geometry

9. Mrs. McConaughyGeometry9 Vocabulary postulateaxiom _______________ _____________________________. A postulate or axiom _______________ _____________________________. is a statement which is accepted as being true.

10. Mrs. McConaughyGeometry10 Line Postulate Through any two points ____________________ ___________________. there is exactly one line

11. Mrs. McConaughyGeometry11 Line Intersection Postulate If two lines intersect,____________________ then they intersect in exactly one point.

12. Mrs. McConaughyGeometry12 Plane Intersection Postulate If two planes intersect,____________________ then they intersect in exactly one line. A B You may find it to be helpful to use two note cards to complete this postulate.

13. Mrs. McConaughyGeometry13 Checking for Understanding A B C E D G F 1.What is the intersection of plane ABED and plane EBCF? 2. Name two planes that intersect in EF. BE DEFG BEFC

14. Mrs. McConaughyGeometry14 Plane Postulate Through any three non-collinear points ____________________ ___________________. there is exactly one plane W O RK

15. Mrs. McConaughyGeometry15 Checking for Understanding Shade the plane that contains T, R, and M. E M O T G R Y

16. Mrs. McConaughyGeometry16 Homework Assignment Pages 13-14: 1-23 odd; 31-43 odd; 48-51, 53-59 odd, 60-69, 70-72 all.