## Corrections

Early printings of the course guide did not include sample responses for each modeling prompt. To access these, visit the modeling prompt pages online.

In the Course Guide, under Scope and Sequence, the Pacing Guide for Geometry Unit 7 was edited to indicate that none of the lessons in that unit are optional.

Unit 1 Narrative. Insert as the second-to-last paragraph: "A blank reference chart is provided for students, and a completed reference chart for teachers. The purpose of the reference chart is to be a resource for students to reference as they make formal arguments. Students will continue adding to it throughout the course. Refer to *About These Materials* in the Geometry course for more information."

Unit 1, Lesson 11, Activity 2. Data Card 1 is updated to remove the bullet about the image of points \(F\) and \(G\).

Unit 1, Lesson 12. One of the learning targets said, "I can describe a reflection by stating the directed line segment." Changed reflection to translation.

Unit 1, Lesson 12, Lesson Summary. Removed stray "1." and "8" from the summary.

Unit 1, Lesson 13. The second bullet should say "clockwise" instead of counterclockwise.

Unit 1, Lesson 14, Info Gap activity. An image of labeled points was missing from the task statement. This image is now in place in the online materials.

Unit 2 Narrative. Add these 2 sentences to the end of the note on materials: “Students will continue to use and add to their reference charts. The completed reference chart for this unit is provided for teacher reference.”

Unit 2, Lesson 1, Practice Problem 6. Updated solution. Part a has the letters in the correct order, and part b uses to a rotation.

Unit 2, Lesson 2, Practice Problem 7. In the solution for the second question, EFAGLK is taken to hexagon ABCIHG.

Unit 2, Lesson 3, Practice Problem 5. The solution to part a now reads, "Angle A is not congruent to angle S as Tyler's statement indicates."

Unit 2, Lesson 3, Practice Problem 6. Choice E is now, "Angle CBA is congruent to angle FED."

Unit 2, Lesson 4, Practice Problem 6. Question 2 refers to quadrilaterals, not pentagons.

Unit 2, Lesson 7, Practice Problem 4. The image is updated to show that AD is congruent to AC.

Unit 2, Lesson 11, Activity 3. In the Are You Ready for More section, students should construct BD to be the same length as BC.

Unit 2, Lesson 11, Practice Problem 3. Choice A now refers to angles CBE and DAE.

Unit 2, Lesson 13, Practice Problem 7. Choices are updated to less ambiguous phrasing.

Unit 2, Lesson 15, Practice Problem 2. The last line of the proof should say line EG is the line of symmetry.

Unit 3, Lesson 3, Activity 3. The image of showed quadrilateral \(ABDC\). The labels for \(C\) and \(D\) are now changed so that it is \(ABCD\) as intended. The solution image is also updated to reflect the change.

Unit 3, Lesson 8, Practice Problem 7. Updated instructions to, "Select **all** true statements given that angle \(AED\) is congruent to angle \(ABC\)."

Unit 3, Lesson 9, Lesson Synthesis. Corrected the first bullet to say that 2 congruent angles in a triangle show that the two triangles are similar.

Unit 3, Lesson 13, Practice Problem 7. Updated choice A to read, "Triangle BDE is congruent to triangle EFC," choice B to read, "Triangle BDE is congruent to triangle DAF," and the solutions to include both of those options.

Unit 3, Lesson 16, Activity 2. In the digital version of the activity, the solution image and value for the third question are updated to match the digital applet.

Unit 4, Lesson 1, Practice Problem 5. Changed the question to, "If segment \(BD\) has length \(\frac{4}{3}\), calculate the length of side \(DE\)."

Unit 4, Lesson 4, Activity 2. The applet linked in the digital launch is updated so that column G now computes opp/adj.

Unit 4, Lesson 8, Practice Problem 8. The question is updated to include that the handball court is 20 feet wide and 34 feet deep. The solution is updated to 7.36 feet away from point C.

Unit 5, Lesson 11, Activity 2. The solution for the volume of solid F is corrected to 30.0 cubic centimeters.

Unit 5, Lesson 13, Practice Problem 7. The solution to the first question is 1,440 cubic centimeters.

Unit 5, Lesson 17, Activity 2. The solution to the Are You Ready for More? question used the wrong units. The solution has been updated.

Unit 5, Lesson 17, Practice Problem 5. Updated the suggested solution cylinder height to 34 units and the suggested rectangular prism to dimensions 2 by 3.2 by 8.

Unit 5, Lesson 18, Activity 3. The image was incorrectly labeled to use the value 14.04. It has been corrected to 14.14.

Unit 5, Lesson 18, Practice Problem 2. The solution for the second question uses 170 square inches so that the ratio is \(\frac{17}{15}\).

Unit 5, Lesson 18, Practice Problem 3. Updated statement values to better values. Radius is 4 units. Volume is \(16\pi\) square units.

Unit 5, End of Unit Assessment, Problem 3. The cone with radius 6 and height 6 is labeled shape C.

Unit 6, Lesson 1, Cool Down. The labels for points B and C are switched to match the description of the problem.

Unit 6, Lesson 2, Activity 3. The sample solution now correctly refers to figures Q, R, and S respectively.

Unit 6, Lesson 3, Activity 2. Graph B is updated so that the vertices of \(F'\) are at \((2,1), (4,1), (4,3)\). Updated rule 3 to be \((\text-2x,y)\)

Unit 6, Lesson 5, Practice Problem 2. The equation of the circle is \( x^2 - 8x + 16 + y^2 + 10y + 25 = 81\) .

Unit 6, Lesson 8, Activity 3. In the blackline master, equation C should be \((x+3)^2 + (y-2)^2 = (y-1)^2\).

Unit 6, Lesson 9, Lesson Synthesis. Each of the bulleted equations has been updated to use 4 instead of 3 to match the graph.

Unit 6, Lesson 11, Activity 3. Corrected solution for part 4 for Are You Ready for More is \((\frac{a+c}{2}, \frac{b}{2})\).

Unit 6, Lesson 15, Activity 3. Corrected solution for part 2 for Are You Ready for More uses the slopes \(\frac{d}{c}\) and \(\frac{f-b}{e-a}\).

Unit 6, Lesson 16, Lesson Summary. Point \((0,w)\) is corrected to \((w,0)\) and matches what is in activity 3

Unit 7, Family Support Materials. The solution for the first question now has a correct reasoning and solution involving \(\pi\).

Unit 7, Lesson 1, Practice Problem 7. Switched points C and D in the image.

Unit 7, Lesson 5, Activity 3. The solution to the second question had the triangles in the wrong order.

Unit 8, Lesson 2, Practice Problem 3. Updated the solution to refer to the letter L instead of P.

Unit 8, Lesson 3, Activity 3. The statement now includes the word "exactly" and the last part should refer to exactly 4 items. In the extension solution, the first outcome in the set should use C3. The solution to the question about exactly 3 items should be \(\frac{4}{24}\)

Unit 8, Lesson 4, Activity 3. The fraction in the solution should be \(\frac{447}{2,234}\). The decimal value was correct. The total number of commuters in Austin is 627 and overall is 1,104.

Unit 8, Lesson 4, Cool-down. The total for the first column should be 19,195.

Unit 8, Lesson Synthesis. Updated solution to second bulleted question to \(\frac{7}{20}\).

Unit 8, Lesson 4, Practice Problem 7. The solution to the second part is 6/16.

Unit 8, Lesson 6, Lesson Summary. The formula now correctly refers to "medium" and "blue" as the correct characteristics.

Unit 8, Lesson 6, Lesson 2. A question referred to Alaska as being one of 12 states in the top left cell of the table. There are only 11 states in the top left cell of the table.

Unit 8, Lesson 6, Practice Problem 6. The solution to part b is 0.67.

Unit 8, Lesson 7. Corrected the learning target to, "I can explain the difference between dependent and independent events."

Unit 8, Lesson 8. Corrected the learning target to, "I can use the multiplication rule \(P(\text{A and B}) = P(\text{A | B}) \boldcdot P(\text{B})\) to find conditional probabilities."

Unit 8, Lesson 9, Activity 2. The Are You Ready for More? did not make sense. A new one is available.

Unit 8, Lesson 9, Activity 3. The calculations in the activity syntheses are corrected. The first bulleted question should use \(\frac{0.015}{0.1}=0.15\) and the third bulleted question should use \(\frac{0.006}{0.15}=0.04\).

Unit 8, Lesson 9, Lesson Synthesis. The last bullet of the lesson synthesis now has a corrected suggested solution \(P(\text{orange} | \text{female}) = \frac{12}{30}\).

Unit 8, Lesson 9, Practice Problem 2. The table is updated to include 50 results and the solutions are updated to match the new values.

Unit 8, Lesson 10, Warm-up. Corrected possible responses. For Set 2, use \(P(B \vert A) = 1\) and for Set 4, \(P(A \text{ and } B) = 0\).

Unit 8, Lesson 10, Practice Problem 2. The third part has been rewritten to be more clear about the events.

Unit 8, Lesson 11. Paper bags are added to the required materials for playing the game.

Unit 8, End of Unit Assessment. Option F had the incorrect inequality. It is corrected to \(P(\text{bus | middle school}) > P(\text{bus | high school})\)

## Lesson Numbering for Learning Targets

In some printed copies of the student workbooks, we erroneously printed a lesson number instead of the unit and lesson number. This table provides a key to match the printed lesson number with the unit and lesson number.

Lesson Number | Unit and Lesson | Lesson Title |
---|---|---|

1 | 1.1 | Build It |

2 | 1.2 | Constructing Patterns |

3 | 1.3 | Construction Techniques 1: Perpendicular Bisectors |

4 | 1.4 | Construction Techniques 2: Equilateral Triangles |

5 | 1.5 | Construction Techniques 3: Perpendicular Lines and Angle Bisectors |

6 | 1.6 | Construction Techniques 4: Parallel and Perpendicular Lines |

7 | 1.7 | Construction Techniques 5: Squares |

8 | 1.8 | Using Technology for Constructions |

9 | 1.9 | Speedy Delivery |

10 | 1.10 | Rigid Transformations |

11 | 1.11 | Defining Reflections |

12 | 1.12 | Defining Translations |

13 | 1.13 | Incorporating Rotations |

14 | 1.14 | Defining Rotations |

15 | 1.15 | Symmetry |

16 | 1.16 | More Symmetry |

17 | 1.17 | Working with Rigid Transformations |

18 | 1.18 | Practicing Point by Point Transformations |

19 | 1.19 | Evidence, Angles, and Proof |

20 | 1.20 | Transformations, Transversals, and Proof |

21 | 1.21 | One Hundred and Eighty |

22 | 1.22 | Now What Can You Build? |

23 | 2.1 | Congruent Parts, Part 1 |

24 | 2.2 | Congruent Parts, Part 2 |

25 | 2.3 | Congruent Triangles, Part 1 |

26 | 2.4 | Congruent Triangles, Part 2 |

27 | 2.5 | Points, Segments, and Zigzags |

28 | 2.6 | Side-Angle-Side Triangle Congruence |

29 | 2.7 | Angle-Side-Angle Triangle Congruence |

30 | 2.8 | The Perpendicular Bisector Theorem |

31 | 2.9 | Side-Side-Side Triangle Congruence |

32 | 2.10 | Practicing Proofs |

33 | 2.11 | Side-Side-Angle (Sometimes) Congruence |

34 | 2.12 | Proofs about Quadrilaterals |

35 | 2.13 | Proofs about Parallelograms |

36 | 2.14 | Bisect It |

37 | 2.15 | Congruence for Quadrilaterals |

38 | 3.1 | Scale Drawings |

39 | 3.2 | Scale of the Solar System |

40 | 3.3 | Measuring Dilations |

41 | 3.4 | Dilating Lines and Angles |

42 | 3.5 | Splitting Triangle Sides with Dilation, Part 1 |

43 | 3.6 | Connecting Similarity and Transformations |

44 | 3.7 | Reasoning about Similarity with Transformations |

45 | 3.8 | Are They All Similar? |

46 | 3.9 | Conditions for Triangle Similarity |

47 | 3.10 | Other Conditions for Triangle Similarity |

48 | 3.11 | Splitting Triangle Sides with Dilation, Part 2 |

49 | 3.12 | Practice With Proportional Relationships |

50 | 3.13 | Using the Pythagorean Theorem and Similarity |

51 | 3.14 | Proving the Pythagorean Theorem |

52 | 3.15 | Finding All the Unknown Values in Triangles |

53 | 3.16 | Bank Shot |

54 | 4.1 | Angles and Steepness |

55 | 4.2 | Half a Square |

56 | 4.3 | Half an Equilateral Triangle |

57 | 4.4 | Ratios in Right Triangles |

58 | 4.5 | Working with Ratios in Right Triangles |

59 | 4.6 | Working with Trigonometric Ratios |

60 | 4.7 | Applying Ratios in Right Triangles |

61 | 4.8 | Sine and Cosine in the Same Right Triangle |

62 | 4.9 | Using Trigonometric Ratios to Find Angles |

63 | 4.10 | Solving Problems with Trigonometry |

64 | 4.11 | Approximating Pi |

65 | 5.1 | Solids of Rotation |

66 | 5.2 | Slicing Solids |

67 | 5.3 | Creating Cross Sections by Dilating |

68 | 5.4 | Scaling and Area |

69 | 5.5 | Scaling and Unscaling |

70 | 5.6 | Scaling Solids |

71 | 5.7 | The Root of the Problem |

72 | 5.8 | Speaking of Scaling |

73 | 5.9 | Cylinder Volumes |

74 | 5.10 | Cross Sections and Volume |

75 | 5.11 | Prisms Practice |

76 | 5.12 | Prisms and Pyramids |

77 | 5.13 | Building a Volume Formula for a Pyramid |

78 | 5.14 | Working with Pyramids |

79 | 5.15 | Putting All the Solids Together |

80 | 5.16 | Surface Area and Volume |

81 | 5.17 | Volume and Density |

82 | 5.18 | Volume and Graphing |

83 | 6.1 | Rigid Transformations in the Plane |

84 | 6.2 | Transformations as Functions |

85 | 6.3 | Types of Transformations |

86 | 6.4 | Distances and Circles |

87 | 6.5 | Squares and Circles |

88 | 6.6 | Completing the Square |

89 | 6.7 | Distances and Parabolas |

90 | 6.8 | Equations and Graphs |

91 | 6.9 | Equations of Lines |

92 | 6.10 | Parallel Lines in the Plane |

93 | 6.11 | Perpendicular Lines in the Plane |

94 | 6.12 | It’s All on the Line |

95 | 6.13 | Intersection Points |

96 | 6.14 | Coordinate Proof |

97 | 6.15 | Weighted Averages |

98 | 6.16 | Weighted Averages in a Triangle |

99 | 6.17 | Lines in Triangles |

100 | 7.1 | Lines, Angles, and Curves |

101 | 7.2 | Inscribed Angles |

102 | 7.3 | Tangent Lines |

103 | 7.4 | Quadrilaterals in Circles |

104 | 7.5 | Triangles in Circles |

105 | 7.6 | A Special Point |

106 | 7.7 | Circles in Triangles |

107 | 7.8 | Arcs and Sectors |

108 | 7.9 | Part to Whole |

109 | 7.10 | Angles, Arcs, and Radii |

110 | 7.11 | A New Way to Measure Angles |

111 | 7.12 | Radian Sense |

112 | 7.13 | Using Radians |

113 | 7.14 | Putting It All Together |

114 | 8.1 | Up to Chance |

115 | 8.2 | Playing with Probability |

116 | 8.3 | Sample Spaces |

117 | 8.4 | Tables of Relative Frequencies |

118 | 8.5 | Combining Events |

119 | 8.6 | The Addition Rule |

120 | 8.7 | Related Events |

121 | 8.8 | Conditional Probability |

122 | 8.9 | Using Tables for Conditional Probability |

123 | 8.10 | Using Probability to Determine Whether Events Are Independent |

124 | 8.11 | Probabilities in Games |