1. Geometry Chapter 1

2. Lesson (1-1)POINTS, LINES, & PLANES What are the 3 BASIC UNDEFINED TERMS IN GEOMETRY? Answer: Point, line, & plane They do not have any shape or size. They are generally defined using examples.

3. Lesson (1-1)POINTS, LINES, & PLANES A point • is a location. • has no shape or size. • is named using one capital letter. EX: A

4. Lesson (1-1)POINTS, LINES, & PLANES A line: • is made up of infinitely many points. • has no thickness.

5. Lesson (1-1)POINTS, LINES, & PLANES A line is named 2 ways. 1. Using 2 capital printed letters representing 2 points on the line E D

6. Lesson (1-1)POINTS, LINES, & PLANES 2. Using a lowercase, cursive letter. line m

7. Lesson (1-1)POINTS, LINES, & PLANES • A plane: • Is a flat surface made up of points that extends infinitely in all directions. • has no thickness.

8. Lesson (1-1)POINTS, LINES, & PLANES A plane is named 2 ways. 1.) using 3 capital printed letters representing 3 points that are not all on the same line  EX. plane BCD or plane DBC or plane CBD, etc

9. Lesson (1-1)POINTS, LINES, & PLANES • 2. using 1 capital, cursive letter plane N

10. Lesson (1-1)POINTS, LINES, & PLANES COLLINEAR POINTS: Points that lie on the same line COPLANAR POINTS: Points that lie on the same plane

11. Lesson (1-1)POINTS, LINES, & PLANES INTERSECTION: The set of points that 2 or more geometric figures have in common 1.) 2 lines intersect in a ________. In the diagram, line aand line b intersect at point R. point

12. Lesson (1-1)POINTS, LINES, & PLANES 2.) A line and a plane intersect in _________________________________ ___________________ EX In the first diagram, In the second diagram, line k and plane Bline p lies completely in intersect at point P.plane Q , so their intersection is line p. a point OR the line if the line lies in the plane.

13. Lesson (1-1)POINTS, LINES, & PLANES line 3.) 2 planes intersect in a. EX

14. Lesson (1-1)POINTS, LINES, & PLANES POSTULATE OR AXIOM: An accepted statement of fact POSTULATE Through any 2 points there is . EX exactly one line

15. Lesson (1-1)POINTS, LINES, & PLANES POSTULATE If 2 lines intersect, then they intersect in . EX exactly one point

16. Lesson (1-1)POINTS, LINES, & PLANES POSTULATE If 2 planes intersect, then they intersect in . exactly one line

17. Lesson (1-1)POINTS, LINES, & PLANES POSTULATE Through any 3 noncollinear points there is . exactly one plane

18. Lesson (1-1)POINTS, LINES, & PLANES

19. Lesson (1-1)POINTS, LINES, & PLANES Assignment: Worksheet Front: #1, 7, 10 – 13, 15, 19 Back: #1, 4, 5, 8, 24, 33, 35, 40, 43

20. Segments, Rays, Parallel Lines, and Planes Segment: The part of a line consisting of 2 endpoints and all points between them Q P consists of points P and Q and all of the points between them To name a line segment use 2 capital letters and a segment above them.

21. Segments, Rays, Parallel Lines, and Planes What is the difference between and ? SEGMENT AB is at the right in blue A B LINE AB is at the right in red A B

22. Segments, Rays, Parallel Lines, and Planes

23. Segments, Rays, Parallel Lines, and Planes

24. Segments, Rays, Parallel Lines, and Planes IN CLASS: Front of worksheet #1,7,10-13,15,19 Assignment: Back of worksheet #1,4,5,8,24,33,35

25. Segments, Rays, Parallel Lines, and Planes Ray: The part of a line consisting of one endpoint and all the points of the line on one side of the endpoint

26. Segments, Rays, Parallel Lines, and Planes Naming a RAY: FIRST: Name the endpoint. SECOND: Name another point on the line closer to the arrow. THIRD: Write  over the letters.

27. Segments, Rays, Parallel Lines, and Planes Name the rays. EX D N M F is not the same as .

28. Segments, Rays, Parallel Lines, and Planes Opposite Rays: 2 collinear rays with the same endpoint Opposite rays ALWAYS form a line! C B A

29. Segments, Rays, Parallel Lines, and Planes and are OPPOSITE RAYS!!! R Q P Together, they make .

30. Segments, Rays, Parallel Lines, and Planes Let’s do #2 – 6, 14, 17, & 18 front of the worksheet together for practice!

31. Segments, Rays, Parallel Lines, and Planes Parallel lines: Coplanar lines that do not intersect Give some real life examples of parallel lines.

32. Segments, Rays, Parallel Lines, and Planes Skew lines: Non-coplanar lines that do not intersect Give some real life examples of skew lines.

33. Segments, Rays, Parallel Lines, and Planes Parallel Planes: Planes that do not intersect Give some real life examples of parallel planes.

34. Segments, Rays, Parallel Lines, and Planes Let’s do #8,9, & 21 on the front of the worksheet.

35. Segments, Rays, Parallel Lines, and Planes Assignment: Do the rest of the back of the worksheet. #2,3,6,7,9-23,25-32,34, 37-39,41,42,44-47 When you have finished this, you should have the front and back of the worksheet completed.

36. Measuring Segments A B C D E F ‒2 ‒1 ‒4 ‒3 4 3 2 1 0 To find the length of a segment, think RIGHT minus LEFT.

37. Measuring Segments A B C D E F ‒2 ‒1 ‒3 4 3 2 1 0 ‒4 The length of is F - E or 4 – 2 = 2.

38. Measuring Segments A B C D E F ‒2 ‒1 ‒4 ‒3 4 3 2 1 0 1. 2. 3. 4.

39. Measuring Segments A B C D E F ‒2 ‒1 ‒3 4 3 2 1 0 ‒4 Remember, RIGHT MINUS LEFT. 1. DF= 4 – 1 = 3 2. CE= 2 – 0 = 2 3. BC= 0 – (‒1) = 1 4. AE= 2 – (-3) = 5

40. Measuring Segments When we found the lengths of the segments on the previous slide, notice how we wrote the lengths. 1. DF= 4 – 1 = 3 2. CE= 2 – 0 = 2 3. BC= 0 – (‒1) = 1 4. AE= 2 – (-3) = 5 We wrote = 3 and not = 3. DF

41. Measuring Segments When we write the length of a segment, we do NOT write “ ― “ over the letters. Find AD & AF. AD = 4 & AF = 7

42. Measuring Segments Congruent segments Segments with the same length

43. Measuring Segments A B C D E F ‒2 ‒1 ‒4 ‒3 4 3 2 1 0 is congruent to what other segments on the number line?

44. Measuring Segments Since all have length 2, they are congruent. The symbol for congruent is ≅ .

45. Measuring Segments SEGMENT ADDITION POSTULATE If 3 points A, B, and C are collinear, and B is between A and C, then AB + BC = AC A B C

46. Measuring Segments If 3 points A, B, and C are collinear and B is between A and C, then AB + BC = AC A B C If AB = 5, and BC = 8, then we write…. 5 + 8 = 13… AC = 13

47. Measuring Segments X, Y, AND Z are collinear and Y lies between X and Z. Sketch a diagram representing this information, and use it to write an equation using the letters X, Y, and Z. Then do the problems on the following slides. X Y Z XY + YZ = XZ

48. Measuring Segments 1. XY = 5, YZ = 3; Find XZ. X Y Z XY + YZ = XZ 5 + 3 = XZ 8 = XZ

49. Measuring Segments 2. XY = 4, XZ = 11; Find YZ. XY + YZ = XZ 4 + YZ = 11 YZ = 7

50. Measuring Segments 3. If XZ = 70, XY = 3a - 2, and YZ = 5a, find the value of a, XY, and YZ. XY + YZ = XZ (3a – 2) + (5a) = 70 8a – 2 = 70 8a = 72 a = 9 XY = 3a - 2 = 3(9) – 2 = 25 YZ = 5a= 5(9) = 45