## 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 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 15, Practice Problem 3. Segment DE is now given as having length 1.

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 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.

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 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.

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

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

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 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
36 2.14 Bisect It
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
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