Plane Geometry Unit 1 – Chapter 1

1. Plane GeometryUnit 1 – Chapter 1 Section 1.1 – Identify Points, Lines, and Planes Day 1

2. Section 1.1 Notes • Undefined Terms – Vocabulary without a formal definition, but overall agreement with what the term means. • Point – representation of a unique location in space. It has no dimension. • Line – connection of an infinite number of points. It has one dimension. P l C A B LINE NOTATION: Line l, Line AB ( AB ), Line ( BC ), or Line AC ( AC )

3. Section 1.1 Notes AB • Compare and Contrast: • Line – Infinite in length, extends endlessly in opposite directions. • Segment – Finite portion of a line that begins and ends at endpoints (points on that line). • Ray – Infinitely long portion of a line that begins at an initial point and extends endlessly in one direction. A B A B AB Endpoint AB A B RAY NOTATION: Point with no arrow head is called endpoint, always list endpoint first and always draw arrow pointing right.

4. Section 1.1 Notes • Extension: • Opposite Rays – two rays that share the same endpoint but extend in exactly opposite directions. They =alwys form a straight line. • What are the opposite rays for the image given? Endpoint H A I HA HI

5. Section 1.1 Notes • Plane – a flat surface that contains an infinite amount of lines and extends endlessly in two directions. M PLANE NOTATION: Plane M, or Plane COW, Plane WOC, Plane OCW W O C PLANE NOTATION: Use any three points that lie on the plane and that do not lie in a line, or if a letter already represents it.

6. Section 1.1 Notes • Collinear Points – points that all lie on the same line. • Coplanar Points – points that all lie on the same plane. B C A D H G O S

7. Section 1.1 Notes A • Identification, name: • The plane: • HOD, DOG, DGH • A Line: • AB, OB, HG, GO, … • A Segment: • GO, AO, BO, HG, … • A Ray: • OG, GH, BA, AB, HG, … D H O G B

8. Section 1.1 Notes E • Identification, Collinear or not? • B, D • C, E • A, D • B, F • F, E, D • A, E, D • D, B, C • C, E, F YES YES YES YES NO NO YES YES A D C B F

9. Section 1.1 Notes E • Identification, Coplanar or not? • B, C, D • A, B, C • F, E, D • E, A, F • A, B, C, D • F, E, D, C • E, A, D, C • B, C, D, E, F YES YES YES YES YES YES NO YES A D C B F

10. Section 1.1 Notes • Intersections: • 2 lines always intersect at a point (Figure 1) • A line that does not lie on a plane can intersect a plane at a point. (Figure 2) E C Intersection Intersection O P C M W Figure 1 Figure 2 F

11. Section 1.1 Notes a • Intersections: (cont.) • 2 Planes always intersect at a line (Figure 3) M Q Intersection: Line a Figure 3

12. CHECK FOR UNDERSTANDING…Time to Draw… • Four coplanar points…three or which are collinear. A D C B

13. CHECK FOR UNDERSTANDING…Time to Draw… • Two coplanar lines that do NOT intersect. F E H B C D

14. CHECK FOR UNDERSTANDING…Time to Draw… • Opposite rays AB and AC. Endpoint A B C AB AC

15. CHECK FOR UNDERSTANDING…Time to Draw… • Three planes that do not intersect. B A M

16. CHECK FOR UNDERSTANDING…Time to Draw… • Three coplanar lines that intersect at the same point. B F H E E C D B

17. CHECK FOR UNDERSTANDING…Time to Draw… • Two planes that intersect one another. a M Q

18. CHECK FOR UNDERSTANDING…Time to Draw… • Two lines that intersect and a third line that does not intersect either of them. E A G D C H B F

19. CHECK FOR UNDERSTANDING…Time to Draw… • Three lines that intersect at a point but are not coplanar. A D H O F G B

20. CONCEPT CHECK • P. 3-5 • #1 – 7 • “Guided Practice”

21. HOMEWORK • P. 5-6 • #3 - 26 • (Omit #12)