Presentation is loading. Please wait.

Presentation is loading. Please wait.

Chapter 1 Discovering Geometry. 1.1 Basic Geometric Figures I. Point A. Geometric figure with no dimensions B. Used to identify a point in space C. Represented.

Similar presentations


Presentation on theme: "Chapter 1 Discovering Geometry. 1.1 Basic Geometric Figures I. Point A. Geometric figure with no dimensions B. Used to identify a point in space C. Represented."— Presentation transcript:

1 Chapter 1 Discovering Geometry

2 1.1 Basic Geometric Figures I. Point A. Geometric figure with no dimensions B. Used to identify a point in space C. Represented by a dot

3 1.1 Basic Geometric Figures I. Point A. Geometric figure with no dimensions B. Used to identify a point in space C. Represented by a dot D. Labeled by a capital letter A

4 II. Line A. Geometric figure having infinite length B. No width or height C. Consists of points D. Represented by a double pointed arrow

5 II. Line A. Geometric figure having infinite length B. No width or height C. Consists of points D. Represented by a double pointed arrow A B

6 II. Line A. Geometric figure having infinite length B. No width or height C. Consists of points D. Represented by a double pointed arrow E. Labeled by any two point that it contains A B

7 II. Line A. Geometric figure having infinite length B. No width or height C. Consists of points D. Represented by a double pointed arrow E. Labeled by any two point that it contains A B AB C

8 II. Line A. Geometric figure having infinite length B. No width or height C. Consists of points D. Represented by a double pointed arrow E. Labeled by any two point that it contains A B AB C ACBC

9 II. Line A. Geometric figure having infinite length B. No width or height C. Consists of points D. Represented by a double pointed arrow E. Labeled by any two point that it contains F. The intersection of two lines is a _______point

10 W P J

11 W P J The intersection of WP and PJ is P.

12 II. Line A. Geometric figure having infinite length B. No width or height C. Consists of points D. Represented by a double pointed arrow E. Labeled by any two point that it contains F. The intersection of two lines is a _______point G. Through any one point there are infinitely many lines

13

14 II. Line A. Geometric figure having infinite length B. No width or height C. Consists of points D. Represented by a double pointed arrow E. Labeled by any two point that it contains F. The intersection of two lines is a _______point G. Through any one point there are infinitely many lines H. Through any two points there is exactly one line

15 III.Plane A. Geometric figure having infinite length and width but no height. B. Represented by a flat rectangular surface C. Planes consist of lines D. Labeled by any three points on the plane

16 Are Points L, K, and M COPLANAR? Yes, they are COPLANAR because they LIE ON THE SAME PLANE P. Is point H, coplanar with points L, K, and M? P Q A B L K M H C No, because it lies on plane Q and points L, K, and M are in different plane, on plane P. NON-COPLANAR points are points that lie in different planes. D PRESENTATION CREATED BY SIMON PEREZ. All rights reserved

17 On what planes does point D lie? P Q A B C D PRESENTATION CREATED BY SIMON PEREZ. All rights reserved

18 On what planes does point D lie? It only lies on plane Q. P Q A C B D PRESENTATION CREATED BY SIMON PEREZ. All rights reserved

19 III.Plane A. Geometric figure having infinite length and width but no height. B. Represented by a flat rectangular surface C. Planes consist of lines D. Labeled by any three points on the plane E. Through any two points there are infinitely many planes F. Through any three points, there is exactly one plane

20 III.Plane A. Geometric figure having infinite length and width but no height. B. Represented by a flat rectangular surface C. Planes consist of lines D. Labeled by any three points on the plane E. Through any two points there are infinitely many planes F. Through any three points, there is exactly one plane G. The intersection of two planes is a_______line H. The intersection of three planes is a _____________ or ___________ linepoint

21 IV.Line Segment A. A piece of a line B. Has two endpoints C. Labeled by its endpoints ∙∙ S T ST

22 V.Ray A. Geometric figure with one endpoint B. Labeled by it’s endpoint and one other point ∙∙ PQ PQ

23

24 1.2 Measuring Line Segments I.“Measure” of a Line Segment A. The distance between its endpoints B. Always positive

25 1.2 Measuring Line Segments 0-2-3-4-523451 A B coordinates ab

26 1.2 Measuring Line Segments 0-2-3-4-523451 A B coordinates ab AB = “the measure of AB” AB= _________7 units

27 1.2 Measuring Line Segments I.“Measure” of a Line Segment A. The distance between its endpoints B. Always positive C. AB = b – a or a - b

28 1.2 Measuring Line Segments 0-2-3-4-523451 A B coordinates ab AB AB = 3 – (-4) AB = 3 + (+4) AB = 7 or AB = -4 – 3 AB = -4 + -3 AB = -7

29 1.2 Measuring Line Segments 0-2-3-4-523451 A B coordinates ab AB AB = 3 – (-4) AB = 3 + (+4) AB = 7 units or AB = -4 – 3 AB = -4 + -3 AB = -7= 7 units

30 Examples P Q PQ 2395 PQ = ________________ 95 – 23= 72 units

31 Examples E F EF -1546 EF = ________________ 46 – (-15)= 61 units OR EF = ________________ -15 – 46 = -61= 61 units

32 Examples R S RS -92-18 RS = ________________ -18 – (-92)= 74 units OR RS = ________________ -92 – (-18) = -74= 74 units | |

33 1.2 Measuring Line Segments II.Segment Addition A. “collinear”= “on the same line” B. If A, B, & C are collinear and B is between A and C, then AB + BC = AC A B C ABBC AC

34 Examples of Segment Addition A carpenter must cut a 54 inch board into two pieces so that one piece is twice as long as the other. What will be the length of the two board after the cut? A B C X2x 54 in. AB + BC = AC x + 2x = 54 3x = 54 3 3

35 Examples of Segment Addition A carpenter must cut a 54 inch board into two pieces so that one piece is twice as long as the other. What will be the length of the two board after the cut? A B C X2x 54 in. AB + BC = AC x + 2x = 54 3x = 54 3 3 3 54 1 3 24 8 0 x = 18 in. 18 in. = 2(18) 36 in.

36 Examples of Segment Addition A 45 foot piece of pipe must be cut so that the longer piece is 9 feet longer than the shorter. What will be the lengths of the two pieces? A B C XX + 9 45 ft. AB + BC = AC x + x + 9 = 45 2x + 9 = 45 2 2 - 9 = -9 2x = 36

37 Examples of Segment Addition A 45 foot piece of pipe must be cut so that the longer piece is 9 feet longer than the shorter. What will be the lengths of the two pieces? A B C XX + 9 45 ft. AB + BC = AC x + x + 9 = 45 2x = 36 2 2 2 36 1 2 16 8 0 x = 18 ft. 18 ft. = 18 + 9 27 ft. 2x + 9 = 45 - 9 = -9

38 1.2 Measuring Line Segments III.Midpoint of a Segment A. If A, B, and C are collinear and AC = CB, then C is the midpoint of AB.

39 1.2 Measuring Line Segments III.Midpoint of a Segment A. If A, B, and C are collinear and AC = CB, then C is the midpoint of AB. A B C

40 1.2 Measuring Line Segments III.Midpoint of a Segment A. If A, B, and C are collinear and AC = CB, then C is the midpoint of AB. A B C 1258 ab B. Midpoint Formula

41 1.2 Measuring Line Segments III.Midpoint of a Segment A. If A, B, and C are collinear and AC = CB, then C is the midpoint of AB. A B C 1258 ab B. Midpoint Formula The midpoint of AB = a + b 2 12 + 58 2 = = 70 2 =35

42 1.2 Measuring Line Segments III.Midpoint of a Segment A. If A, B, and C are collinear and AC = CB, then C is the midpoint of AB. A B C -1535 ab B. Midpoint Formula The midpoint of AB = a + b 2 -15 + 35 2 = = 20 2 =10

43 1.2 Measuring Line Segments III.Midpoint of a Segment A. If A, B, and C are collinear and AC = CB, then C is the midpoint of AB. A B C -84-12 ab B. Midpoint Formula The midpoint of AB = a + b 2 -84 + -12 2 = = -96 2 = -48

44

45 Examples of Segment Addition A carpenter must cut a 65 inch board into two pieces so that one piece is five inches more than twice the length of the other. What will be the length of the two board after the cut? A B C X2x+5 65 in. AB + BC = AC x + 2x+5 = 65

46 1.3 Measuring Angles A. Using a Protractor ACUTE Angle less than 90 60 ° °

47 1.3 Measuring Angles A. Using a Protractor RIGHT Angle 90 °

48 1.3 Measuring Angles A. Using a Protractor OBTUSE Angle Greater than 90 ° 140 °

49 1.3 Measuring Angles A. Using a Protractor ° 120

50 1.3 Measuring Angles A. Using a Protractor A B C D E F O

51 1.3 Measuring Angles A.Using a Protractor B. Angle Addition A B C D

52 1.3 Measuring Angles A.Using a Protractor B. Angle Addition A B C D m ABD + m DBC = m ABC

53 A B C D m ABD + m DBC = m ABC A 70 angle is divided into two smaller angles such that the larger angle is two more than three times the smaller. 70 ° ° x 3x + 2 x + 3x +2 = 70 4x + 2 = 70 –2 4x = 68___ 4 4 x = 17 17 ° 3(17) + 2 53 °

54 1.3 Measuring Angles A.Using a Protractor B. Angle Addition C. Vertical Angle Conjecture “ the vertical angles formed by intersecting lines have equal measure”

55

56 1.4 Special Angles A.Complementary Angles A pair of angles whose sum is 90 º 1 2

57 1.4 Special Angles A.Complementary Angles A pair of angles whose sum is 90 º 1 2

58 1.4 Special Angles B.Supplementary Angles A pair of angles whose sum is 180° 1 2

59 1.4 Special Angles B.Supplementary Angles 12

60 An angle is four times it’s compliment. Find both angles. x 4x x + 4x = 90 5x = 90 x = 18 18° 4(18) = 72°

61

62 1.5 Parallel and Perpendicular Lines A.Parallel Lines Lines on the same plane that do not intersect l m l | | m

63 1.5 Parallel and Perpendicular Lines A.Parallel Lines Lines on the same plane that do not intersect B.Perpendicular Lines Two lines that intersect at a right angle

64 1.5 Parallel and Perpendicular Lines k j k j

65 1.5 Parallel and Perpendicular Lines C.Corresponding Angles 123 m<1 = m<2 = m<3

66 1.5 Parallel and Perpendicular Lines C.Corresponding Angles 12 m<1 = m<2 = m<3 (3x+20)(5x -10) 3x + 20 = 5x – 10 -3x 20 = 2x – 10 +10 = + 10 30 = 2x 2 2 15 = x m<1 = 3(15) +20 4545 65º m<2 = 5(15) – 10 75 65º

67 1.5 Parallel and Perpendicular Lines C.Corresponding Angles 12 m<1 = m<2 = m<3 (6x+30) (3x +57) 6x + 30 = 3x + 57 -3x 3x + 30 = 57 - 30 = - 30 3x = 27 3 3 x = 9 m<1 = 6(9) +30 5454 84º m<2 = 3(9) + 57 27 84º

68 1.5 Parallel and Perpendicular Lines C.Corresponding Angles 12 m<1 = m<2 = m<3 (9x+50) (4x +39) 9x + 50 + 4x + 39 = 180 13x +89 = 180 - 89 - 89 13x = 91 13 13 x = 7 m<1 = 9(7) +50 6363 113º m<2 = 4(7) + 39 28 67º

69


Download ppt "Chapter 1 Discovering Geometry. 1.1 Basic Geometric Figures I. Point A. Geometric figure with no dimensions B. Used to identify a point in space C. Represented."

Similar presentations


Ads by Google