Topic Review — Shape Transformations
Review Questions
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Translations Fluency
- Translate (4, 7) by right 3, down 5.
- Translate (−2, 1) by left 4, up 6.
- Translate (0, −3) by right 7, up 2.
- Triangle A(1, 2), B(3, 2), C(2, 5) is translated right 2, down 4. Find A′, B′, C′.
- Describe the translation that maps (5, 3) to (1, 8).
- Describe the translation that maps (−1, −2) to (3, 4).
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Reflections Fluency
- Reflect (5, −3) over the x-axis.
- Reflect (−4, 6) over the y-axis.
- Reflect (3, 7) over the line y = x.
- Reflect (0, −5) over the x-axis.
- Triangle P(2, 1), Q(4, 1), R(3, 4) is reflected over the y-axis. Find P′, Q′, R′.
- Point A(6, 2) maps to A′(2, 6). What mirror line was used?
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Rotations Fluency
- Rotate (4, 3) by 90° clockwise about the origin.
- Rotate (−2, 5) by 90° anticlockwise about the origin.
- Rotate (6, −1) by 180° about the origin.
- Rotate (3, 0) by 270° clockwise about the origin.
- Triangle A(1, 2), B(3, 2), C(2, 5) is rotated 90° CW about the origin. Find A′, B′, C′.
- Point P(2, −3) maps to P′(3, 2) after a rotation about the origin. What rotation was applied?
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Identify the Transformation Understanding
Identify whether each mapping is a translation, reflection, or rotation. Justify your answer.
- A(2, 3) → A′(5, 1); B(4, 3) → B′(7, 1); C(3, 5) → C′(6, 3).
- A(1, 4) → A′(1, −4); B(3, 4) → B′(3, −4); C(2, 7) → C′(2, −7).
- A(2, 1) → A′(1, −2); B(4, 1) → B′(1, −4); C(3, 3) → C′(3, −3).
- Name two properties that are preserved by ALL three transformations studied in this topic.
- Which transformation changes the orientation of a shape?
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Mixed Coordinate Problems Understanding
- Point A(3, 4) is reflected over the x-axis to get A′, then A′ is translated right 2, up 1 to get A′′. Find A′′.
- Point B(1, 5) is rotated 90° CW to get B′, then reflected over the y-axis to get B′′. Find B′′.
- Triangle with vertices (0, 0), (4, 0), (2, 3) is rotated 180° about the origin. List the image vertices.
- Image triangle has vertices (−3, 1), (−6, 1), (−4, 4). It was created by reflecting an original triangle over the y-axis. Find the original vertices.
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Transformation Summary and Reasoning Problem Solving
- Complete the table:
Transformation Changes position? Changes orientation? Changes size/shape? Translation ? ? ? Reflection ? ? ? Rotation ? ? ? - A designer tiles a floor using a single triangle shape and three transformations. Describe how you could use a translation, a reflection, and a rotation to fill a rectangular section of floor with the tile and its transformed images.
- Point P(a, b) is rotated 90° CW and then 90° ACW about the origin. What are the final coordinates? Explain why.
- Complete the table:
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Successive Transformations Problem Solving
- Point A(2, 5) is reflected over the y-axis to get A′, then rotated 90° CW about the origin to get A′′. Find A′′.
- Point B(−3, 4) is translated right 5, down 2 to get B′, then reflected over the x-axis to get B′′. Find B′′.
- Triangle with vertices (0,0), (3,0), (0,4) is rotated 180° about the origin. List the image vertices and describe what happens to the shape’s orientation.
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Translation Vectors Understanding
- Write the translation vector that maps (2, 3) to (7, 1).
- Write the translation vector that maps (−4, 5) to (−1, −2).
- A shape is translated by vector (right 3, up 4). What vector would translate it back to the original position?
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Reflection Lines Understanding
- Point (3, −5) is reflected to (−3, −5). What is the mirror line?
- Point (4, 2) is reflected to (2, 4). What is the mirror line?
- Point (−1, 6) is reflected to (−1, −6). What is the mirror line?
- Describe how you can tell which mirror line was used given the original and image coordinates.
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Congruence and Transformations Fluency
- What does it mean for two shapes to be congruent?
- Do translations, reflections, and rotations all produce congruent shapes? Explain.
- If a shape is congruent to another, does it have to be the same orientation?
- True or False: a reflection always changes the orientation of a shape.