# 12.3: Geometric Translations

**At Grade**Created by: CK-12

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**Practice**Geometric Translations

What if Lucy lived in San Francisco, , and her parents lived in Paso Robles, ? She will be moving to Ukiah, , in a few weeks. All measurements are in miles. Find:

a) The component form of and .

b) Lucy’s parents are considering moving to Fresno, . Find the component form of and .

c) Is Ukiah or Paso Robles closer to Fresno?

After completing this Concept, you'll be able to answer these questions.

### Watch This

CK-12 Foundation: Chapter12TranslationsA

Learn more about translations by watching the video at this link.

### Guidance

*
A
*
**
transformation
**

*is an operation that moves, flips, or changes a figure to create a new figure. A*

*rigid transformation**is a transformation that preserves size and shape. The rigid transformations are: translations (discussed here), reflections, and rotations. The new figure created by a transformation is called the*

*image**. The original figure is called the*

*preimage**. Another word for a rigid transformation is an*

*isometry**. Rigid transformations are also called*

*congruence transformations**. If the preimage is , then the image would be labeled , said “a prime.” If there is an image of , that would be labeled , said “a double prime.”*

A
**
translation
**
is a transformation that moves every point in a figure the same distance in the same direction. In the coordinate plane, we say that a translation moves a figure
units and
units. Another way to write a translation rule is to use vectors. A
**
vector
**
is a quantity that has direction and size.

In the graph below, the line from
to
, or the distance traveled, is the vector. This vector would be labeled
because
is the
**
initial point
**
and
is the
**
terminal point
**
. The terminal point always has the arrow pointing towards it and has the half-arrow over it in the label.

The
**
component form
**
of
combines the horizontal distance traveled and the vertical distance traveled. We write the component form of
as
because
travels 3 units to the right and 7 units up. Notice the brackets are pointed,
, not curved.

#### Example A

Graph square and . Find the image after the translation . Then, graph and label the image.

The translation notation tells us that we are going to move the square to the left 2 and up 3.

#### Example B

Name the vector and write its component form.

The vector is . From the initial point to terminal point , you would move 6 units to the left and 4 units up. The component form of is .

#### Example C

Name the vector and write its component form.

The vector is . The component form of is .

Watch this video for help with the Examples above.

CK-12 Foundation: Chapter12TranslationsB

#### Concept Problem Revisited

a)

b)

c) You can plug the vector components into the Pythagorean Theorem to find the distances. Paso Robles is closer to Fresno than Ukiah.

### Vocabulary

A
**
transformation
**
is an operation that moves, flips, or otherwise changes a figure to create a new figure. A

**(also known as an**

*rigid transformation***or**

*isometry***) is a transformation that does not change the size or shape of a figure. The new figure created by a transformation is called the**

*congruence transformation***. The original figure is called the**

*image***. A**

*preimage***is a transformation that moves every point in a figure the same distance in the same direction. A**

*translation***is a quantity that has direction and size. The**

*vector***of a vector combines the horizontal distance traveled and the vertical distance traveled.**

*component form*### Guided Practice

1. Find the translation rule for to .

2. Draw the vector with component form .

3. Triangle has coordinates and . Translate using the vector . Determine the coordinates of .

4. Write the translation rule for the vector translation from #3.

**
Answers:
**

1. Look at the movement from to . is (-3, 3) and is (3, -1). The change in is 6 units to the right and the change in is 4 units down. Therefore, the translation rule is .

2. The graph is the vector . From the initial point it moves down 5 units and to the right 2 units.

3. It would be helpful to graph . To translate , add each component of the vector to each point to find .

4. To write as a translation rule, it would be .

### Practice

- What is the difference between a vector and a ray?

Use the translation for questions 2-8.

- What is the image of ?
- What is the image of ?
- What is the preimage of ?
- What is the image of ?
- What is the preimage of ?
- What is the image of ?
- Plot , and from the questions above. What do you notice? Write a conjecture.

The vertices of are and . Find the vertices of , given the translation rules below.

In questions 13-16, is the image of . Write the translation rule.

For questions 17-19, name each vector and find its component form.

- The coordinates of are and . Translate using the vector and find the coordinates of .
- The coordinates of quadrilateral are and . Translate using the vector and find the coordinates of .

Center of Rotation

In a rotation, the center of rotation is the point that does not move. The rest of the plane rotates around this fixed point.Image

The image is the final appearance of a figure after a transformation operation.Preimage

The pre-image is the original appearance of a figure in a transformation operation.Transformation

A transformation moves a figure in some way on the coordinate plane.Translation

A translation is a transformation that slides a figure on the coordinate plane without changing its shape, size, or orientation.### Image Attributions

## Description

## Learning Objectives

Here you'll learn what a translation is and how to perform translation rules.