1. Cover Slide Identifying Points, Lines And Planes

2. 3 Undefined Terms Points, Lines, and Planes The 3 Undefined Terms of Geometry Points, Lines, and Planes undefined geometric terms described instead of defined a starting “point” for us to build on used in the definitions of more complex geometric figures three most basic figures in geometry

3. Points Points, Lines, and Planes Points Examples: a dot or a star Named: usually by a capital letter A B C Points A, B and C no actual size sometimes represented by objects that do have size all geometric figures are composed of points

4. Lines Points, Lines, and Planes Named: usually by a lower-case letter (sometimes script) by any two points on the line and the line symbol Example: the dotted lines on a street or highway or b b E D line DE line ED DE ED series of points extending indefinitely in two directions no thickness or width represented by a figure that does have thickness Ways to name the line to the left: Lines

5. Planes Points, Lines, and Planes Example: a ceiling or a wall Named: usually by a capital letter (sometimes script) by any three points that are not on the same line but are in that plane or K plane RST Planes a flat surface no thickness or width extends indefinitely in all directions Ways to name the plane to the right: K R S T

6. Collinear/Noncollinear Definitions Collinear points that lie on the same line Noncollinear points that do not lie on the same line C B D B, C, and D are collinear E F G E, F, and G are noncollinear One line could not pass through all 3 points.

7. Coplanar/Noncoplanar Definitions Coplanar points that lie in the same plane Noncoplanar points that do not lie in the same plane C B D A, B, C, and D are coplanar E F G E, F, G, and H are noncoplanar A H

8. Space/Intersection Definitions Space Intersection the intersection of two figures is the set of points that are in both figures the set of all points three-dimensional points, lines, and planes are contained in space Some examples of intersection will be demonstrated on the following slides.

9. Relation line-point, 2 lines Point, Line, and Plane - Relationships S R d a b S is on d. S is in d. d passes through S. d contains S. The intersection of d and S is S. The intersection of a and b is R. a and b intersect at R. a and b intersect in R. both a and b contain R.

10. Relation line-plane, 2 planes Point, Line, and Plane - Relationships b and D are in W. W contains b and D. The intersection of a and W is D. C B X Y a intersects W at D. D W b a a and b do not intersect. BC is in Y and X. Y and X both contain BC. Y and X intersect in BC. All points on BC are in Y and X. The intersection of Y and X is BC.

11. Q & A prob. 1-6 (T or F) Q & A A B C D E H F N J K L M Determine whether each statement is true or false. 1. 2. 3. 4. 5. 6. A, M, and C are collinear. F, L, B, and C are coplanar. D, M, and B are coplanar. A, C, and E are collinear. E, L, K, and B are coplanar. A, C, and E are coplanar. true false true

12. Q & A prob. 1-5 Q & A A B C D E H F N J K L M Refer to the figure at the left to answer each question. B planes BDH & EDH C, K planes FAD, FED, BND C 1. 2. 3. 4. 5. Name 3 planes that intersect at D. Name all points coplanar with E, H, and B. Name the intersection of BC and NB. Name two planes that intersect in DH. Name the intersection of BC and plane EFA.