**Vocabulary**

image, preimage, reflection, rigid motion, transformation

**TEKS** 8(1)(D), 8(10)(A)

A **reflection**, or flip, is a rigid motion that flips a figure over a line called the **line of reflection.**

If a point *A* is on the line of reflection, then its image *
A′]* is itself (

If a point *B* is not on the line of reflection, then *B* and *B*′ are on opposite sides of the line of reflection. They are on a line perpendicular to the line of reflection, and are the same distance from the line of reflection.

**TEKS** 8(1)(D), 8(10)(A)

**Example Recognizing Reflections**

Determine which transformation is a reflection.

**Solution**

The second transformation is a reflection across the *y*-axis.

Digits, Grade 8, Volume 2, Homework Helper
Unit D: Two-Dimensional Shapes
Unit E: Measurement and Data
Math Symbols
Formulas Measures
Properties

Topic 11: Scatter Plots
Topic 12: Samples

Unit F: Personal Financial Literacy
Unit G: Step-Up Lessons
- 11-1: Interpreting a Scatter Plot
- 11-1: TEKS Practice
- 11-2: Constructing a Scatter Plot
- 11-2: TEKS Practice
- 11-3: Investigating Patterns – Association
- 11-3: TEKS Practice
- 11-4: Linear Models – Fitting a Straight Line
- 11-4: TEKS Practice
- 11-5: Using the Equation of a Linear Model
- 11-5: TEKS Practice
- 11-6: Additional Problem Solving
- 11-6: TEKS Practice

Topic 15: Step-Up Lessons

English/Spanish Glossary
Formulas
- 15-1: Solving Equations Using the Distributive Property
- 15-1: TEKS Practice
- 15-2: Solutions – One, None, or Infinitely Many
- 15-2: TEKS Practice
- 15-3: Exponents and Multiplication
- 15-3: TEKS Practice
- 15-4: Exponents and Division
- 15-4: TEKS Practice
- 15-5: Operations with Numbers Expressed in Scientific Notation
- 15-5: TEKS Practice
- 15-6: Solving Simultaneous Linear Equations Using Addition
- 15-6: TEKS Practice
- 15-7: Solving Simultaneous Linear Equations Using Subtraction
- 15-7: TEKS Practice