Answer Key
Chapter 8 – Geometry 8.1
Angle Classification
Answers 1. Straight
2. Obtuse
3. Acute
4. Acute
5. Right
6. Obtuse
7. Right
8. Obtuse
9. Acute
10. Obtuse
11. Right
12. Straight
13. acute
14. Acute
15. Obtuse
8.2
Angle Pairs
Answers 1. Complementary
2. Complementary
3. Supplementary
4. Supplementary
5. Neither
6. Supplementary
7. Supplementary
8. Neither
9. Neither
10. Complementary
11. Neither
12. Neither
13. Complementary
14. Neither
15. Neither
8.3
Supplementary and Complementary Angle Pairs
Answers 1. 27°
2. 7°
3. 87°
4. 67°
5. 20°
6. 61°
7. 24°
8. 3°
9. 147°
10. 77°
11. 107°
12. 102°
13. 81°
14. 70°
15. 53°
8.4
Vertical Angles
Answers 1. Intersecting
2. Parallel
3. Intersecting
4. Perpendicular
5. Parallel
6. Perpendicular
7. Intersecting
8. Vertical
9. Adjacent
10. Adjacent
11. Vertical
12. Vertical
13. Adjacent
14. Vertical
15. Adjacent
16. 95°
17. 55°
18. 107°
19. 98°
20. 67°
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Answer Key
Chapter 8 – Geometry 8.5
Parallel and Perpendicular Lines
Answers 1. True
2. False
3. False
4. True
5. False
6. True
7. True
8. True
9. True
10. Intersecting
11. Intersecting
12. Parallel
13. Parallel
14. Intersecting
15. Parallel
8.6
Corresponding Angles
Answers 1. Angles next to each other 2. Angles opposite each other with the same measure 3. Lines that will never intersect 4. Lines that intersect at a 90 degree angle 5. An angle pair whose sum is 180° 6. An angle pair whose sum is 90° 7. Angles formed when two parallel lines are intersected 8. vertical 9. Angle P 10. Angle Q 11. True 12. False 13. False 14. 4 15. No
CK-12 Middle School Math Concepts - Grade 7
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Answer Key
Chapter 8 – Geometry 8.7
Triangle Sum Theorem
Answers 1. 90°
2. 60°
3. 75°
4. 35°
5. 65°
6. 15°
7. 30°
8. 10°
9. 25°
10. 80°
11. 60°
12. 55°
13. 85°
14. 95°
15. 50°
8.8
Triangle Classification
Answers 1. 80°
2. 72°
3. 55°
4. Obtuse
5. Acute
6. Acute
7. Right
8. Scale
9. Equilateral
10. Scalene
11. Isosceles
12. Obtuse
13. false
14. True
15. True
16. True
17. False
18. False
19. true
20. True
8.9
Quadrilateral Classification
Answers 1. Trapezoid
2. Parallelogram
3. Square
4. Rhombus
5. Rectangle
6. square
7. Parallelogram
8. Trapezoid
9. Rhombus
10. Quadrilateral
11. trapezoid
12. Square
13. Rectangle or square
14. Square or rhombus
15. rectangle
8.10
Polygon Classification
Answers 1. square, trapezoid Angle F = 90°, Angle E = 90°, Angle G = 90°, Angle H = 55°, Angle I = 90° 2. True
3. True
4. True
5. False
6. False
7. True
8. Yes
9. No
10. No
11. No
12. Yes
13. No
14. Yes
15. Yes
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Answer Key
Chapter 8 – Geometry 8.11
Regular and Irregular Polygons
Answers 1. Trapezoid
2. Rectangle
3. Square
4. Square
5. square, trapezoid Angle F = 90°, Angle E = 90°, Angle G = 90°, Angle H = 55°, Angle I = 90° 6. True
7. True
8. True
9. False
10. False
11. True
12. True
13. False
14. Regular hexagon
15. Irregular heptagon
16. Regular pentagon
17. Irregular octagon
8.12
Congruent Figures
Answers 1. Angle S 2. ST 3. Angle Q 4. 2 cm 5. 85° 6. 85° 7. True 8. No 9. Yes 10. No 11. No 12. No 13. Yes, congruent figures have the same measure 14. Congruent figures have the same size and shape 15. False
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Answer Key
Chapter 8 – Geometry 8.13
Similarity
Answers 1. Congruent 2. Similar 3. Similar 4. Neither 5. Congruent 6. Neither 7. True 8. False 9. False 10. Two equal ratios form a proportion 11. True 12. Similar figures have the same shape but different size 13. Congruent 14. Having exactly the same size, shape and measure 15. True
8.14
Scale Factor of Similar Polygons
Answers 1. 1/5
2. 1/6
3. 1/2.5
4. 1/3.5
5. 3/1
6. 4/1
7. ¼
8. 2/1
9. 3/1
10. 8/1
11. 5/1
12. 6/1
13. 2/1
14. 3/1
15. 1/3
CK-12 Middle School Math Concepts - Grade 7
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Answer Key
Chapter 8 – Geometry 8.15
Unknown Measures of Similar Figures
Answers 1. 3 cm
2. 56 inches
3. 21
4. 3
5. 4/3
6. 8/1
7. 9/1
8. 24 cm
9. 19.5 in
10. 4500 ft
11. 9000 ft
12. 7500 ft
13. 2250 ft
14. 3750 ft
15. 5250 ft
16. 7500 ft
8.16
Rigid Transformations
Answers 1. Translation
2. Rotation
3. Translation
4. Reflection
5. Rotation
6. Translation
7. Reflection
8. Rotation
9. Line
10. Rotational
11. Line
12. Line
13 – 15 Answers Vary
8.17
Lines of Symmetry
Answers 1. False
2. True
3. False
4. True
5. True
7. True
8. True
9. Line
10. Rotational 11. Line
6. False 12. Line
13 – 15 Answers Vary
8.18
Transformation Classification
Answers 1. Translation
2. Rotation
3. Translation
4. Reflection
5. Rotation
6. Translation
7. Reflection
8. Translation
9. True
10. (5, 3)(7,7)(8,2)
11. (3,3)(7,7)(8, 2)
12. (6, 3)(7,7)(8, 2)
13. (10, -1)(7,7)(8, 2)
14. (11, 4)(7,7)(8, 2)
15. (10, 5)(7,7)(8, 2)
CK-12 Middle School Math Concepts - Grade 7
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Chapter 8 – Geometry 8.19
Answer Key
Translations, Rotations and Reflections
Answers 1. (-1, 5)(-5, 1)(-1, -3) 2. (3, 2)(-1, -2)(3, -6) 3. (-4, 2)(-10, -2)(-6, -6) 4. (-7, 2)(-11, -2)(-7,-6) 5. (1,1)(-3, -3)(1, -7) 6. (-2, 4)(-6, 0)(-2, -4) 7. (0, 5)(-4, 1)(0, -3) 8. (2, 1)(-2, 5)(-6, 1) 9. (1, -2)(5, 2)(1, 6) 10. (-1, -2)(-5, 2)(-1, 6) 11. (1, 2)(5, -2)(1, -6) 12. (2, 7)(-2, 3)(2, -1) 13. (-5, -4)(-11, -8)(-5, -12) 14. True 15. False
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