Learn on PengiSaxon Math, Course 2Chapter 8: Lessons 71-80, Investigation 8

Lesson 80: Transformations

In Saxon Math Course 2, Grade 7 students learn about the three types of geometric transformations — reflection, translation, and rotation — and how to perform each on figures plotted on a coordinate plane. The lesson covers how flipping a shape across the x- or y-axis produces a reflection, sliding it to a new position creates a translation, and turning it around a center of rotation results in a rotation. Students practice identifying and drawing transformed figures using ordered pairs and prime notation for image vertices.

Section 1

📘 Transformations

New Concept

Transformations move or resize geometric figures. The main types are reflections (flips), translations (slides), rotations (turns), and dilations (resizing).

MovementName
flipreflection
slidetranslation
turnrotation

What’s next

This is your introduction to the four types of transformations. Next, you'll work through examples showing how to graph each one on a coordinate plane.

Section 2

Transformations

Property

These 'flips, slides, and turns' are called transformations.
| Movement | Name |
| :--- | :--- |
| flip | reflection |
| slide | translation |
| turn | rotation |

Examples

A flip over the y-axis is a reflection: A point at (2,3)(2, 3) moves to (2,3)(-2, 3).
A slide 4 units down is a translation: A point at (1,1)(1, 1) moves to (1,3)(1, -3).
A 180180^\circ spin around the origin is a rotation: A point at (2,5)(2, 5) moves to (2,5)(-2, -5).

Explanation

Transformations are the super moves for shapes! You can flip them like a pancake (reflection), slide them like a video game character (translation), or spin them like a top (rotation). These moves change a figure's position or orientation on the page, but the shape itself stays the exact same size, making it congruent.

Section 3

Reflection

Property

A reflection of a figure in a line (a 'flip') produces a mirror image of the figure that is reflected.

Examples

Reflecting ABC\triangle ABC with vertices A(1,4),B(3,4),C(1,1)A(1, 4), B(3, 4), C(1, 1) in the x-axis gives A(1,4),B(3,4),C(1,1)A'(1, -4), B'(3, -4), C'(1, -1).
Reflecting the point P(2,5)P(-2, 5) in the y-axis results in the point P(2,5)P'(2, 5).
When you reflect a point (x,y)(x,y) across the x-axis, the new point becomes (x,y)(x, -y).

Explanation

Imagine a puddle on the ground. A reflection is your shape's twin looking back at it from the other side of a line, like the edge of the puddle. Every point is the same distance from the line, just on the opposite side. This creates a perfect, spooky mirror image of the original figure!

Section 4

Translation

Property

A translation 'slides' a figure to a new position without turning or flipping the figure.

Examples

Translating rectangle ABCDABCD with vertex A(2,2)A(2, 2) left 6 units and down 3 units moves AA to A(4,1)A'(-4, -1).
If point P(0,5)P(0, 5) is translated right 2 units and up 1 unit, its new position is P(2,6)P'(2, 6).
To translate a point (x,y)(x, y) by (a,b)(a, b), the new coordinates are (x+a,y+b)(x+a, y+b).

Explanation

A translation is like pushing a chess piece across the board. The shape doesn't twist, turn, or flip; it just glides to a new location. Every single point on the shape moves the exact same distance and in the exact same direction. It's a perfectly synchronized group trip for all the points!

Book overview

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Chapter 8: Lessons 71-80, Investigation 8

  1. Lesson 1

    Lesson 71: Finding the Whole Group When a Fraction is Known

  2. Lesson 2

    Lesson 72: Implied Ratios

  3. Lesson 3

    Lesson 73: Multiplying and Dividing Positive and Negative Numbers

  4. Lesson 4

    Lesson 74: Fractional Part of a Number, Part 2

  5. Lesson 5

    Lesson 75: Area of a Complex Figure, Area of a Trapezoid

  6. Lesson 6

    Lesson 76: Complex Fractions

  7. Lesson 7

    Lesson 77: Percent of a Number, Part 2

  8. Lesson 8

    Lesson 78: Graphing Inequalities

  9. Lesson 9

    Lesson 79: Estimating Areas

  10. Lesson 10Current

    Lesson 80: Transformations

  11. Lesson 11

    Investigation 8: Probability and Odds, Compound Events, Experimental Probability

Lesson overview

Expand to review the lesson summary and core properties.

Expand

Section 1

📘 Transformations

New Concept

Transformations move or resize geometric figures. The main types are reflections (flips), translations (slides), rotations (turns), and dilations (resizing).

MovementName
flipreflection
slidetranslation
turnrotation

What’s next

This is your introduction to the four types of transformations. Next, you'll work through examples showing how to graph each one on a coordinate plane.

Section 2

Transformations

Property

These 'flips, slides, and turns' are called transformations.
| Movement | Name |
| :--- | :--- |
| flip | reflection |
| slide | translation |
| turn | rotation |

Examples

A flip over the y-axis is a reflection: A point at (2,3)(2, 3) moves to (2,3)(-2, 3).
A slide 4 units down is a translation: A point at (1,1)(1, 1) moves to (1,3)(1, -3).
A 180180^\circ spin around the origin is a rotation: A point at (2,5)(2, 5) moves to (2,5)(-2, -5).

Explanation

Transformations are the super moves for shapes! You can flip them like a pancake (reflection), slide them like a video game character (translation), or spin them like a top (rotation). These moves change a figure's position or orientation on the page, but the shape itself stays the exact same size, making it congruent.

Section 3

Reflection

Property

A reflection of a figure in a line (a 'flip') produces a mirror image of the figure that is reflected.

Examples

Reflecting ABC\triangle ABC with vertices A(1,4),B(3,4),C(1,1)A(1, 4), B(3, 4), C(1, 1) in the x-axis gives A(1,4),B(3,4),C(1,1)A'(1, -4), B'(3, -4), C'(1, -1).
Reflecting the point P(2,5)P(-2, 5) in the y-axis results in the point P(2,5)P'(2, 5).
When you reflect a point (x,y)(x,y) across the x-axis, the new point becomes (x,y)(x, -y).

Explanation

Imagine a puddle on the ground. A reflection is your shape's twin looking back at it from the other side of a line, like the edge of the puddle. Every point is the same distance from the line, just on the opposite side. This creates a perfect, spooky mirror image of the original figure!

Section 4

Translation

Property

A translation 'slides' a figure to a new position without turning or flipping the figure.

Examples

Translating rectangle ABCDABCD with vertex A(2,2)A(2, 2) left 6 units and down 3 units moves AA to A(4,1)A'(-4, -1).
If point P(0,5)P(0, 5) is translated right 2 units and up 1 unit, its new position is P(2,6)P'(2, 6).
To translate a point (x,y)(x, y) by (a,b)(a, b), the new coordinates are (x+a,y+b)(x+a, y+b).

Explanation

A translation is like pushing a chess piece across the board. The shape doesn't twist, turn, or flip; it just glides to a new location. Every single point on the shape moves the exact same distance and in the exact same direction. It's a perfectly synchronized group trip for all the points!

Book overview

Jump across lessons in the current chapter without opening the full course modal.

Continue this chapter

Chapter 8: Lessons 71-80, Investigation 8

  1. Lesson 1

    Lesson 71: Finding the Whole Group When a Fraction is Known

  2. Lesson 2

    Lesson 72: Implied Ratios

  3. Lesson 3

    Lesson 73: Multiplying and Dividing Positive and Negative Numbers

  4. Lesson 4

    Lesson 74: Fractional Part of a Number, Part 2

  5. Lesson 5

    Lesson 75: Area of a Complex Figure, Area of a Trapezoid

  6. Lesson 6

    Lesson 76: Complex Fractions

  7. Lesson 7

    Lesson 77: Percent of a Number, Part 2

  8. Lesson 8

    Lesson 78: Graphing Inequalities

  9. Lesson 9

    Lesson 79: Estimating Areas

  10. Lesson 10Current

    Lesson 80: Transformations

  11. Lesson 11

    Investigation 8: Probability and Odds, Compound Events, Experimental Probability