Rotations Lesson, TEKS 8.10C

​Do your Warm-Up!

What is our TEKS?

TEKS 8.10C:

The student will explain the effect of rotations limited to 90°, 180°, 270°, and 360° as applied to two‐dimensional shapes on a coordinate plane using an algebraic representation.

Rotations, TEKS 8.10C (R)

It's time for our lesson . . .

Rotations

You can take notes in your journal or lined paper, but be sure to pay attention to the IXL video.

Open Ended

What is one thing that you learned from the video?

Rotations:

A rotation is a type of transformation that takes each point in a figure and rotates (turns) it a certain number of degrees around a given point.

Multiple Choice

Which word can be used to describe a rotation?

• Flip

• Turn

• Slide

• Stretch

Open Ended

Where do we see rotations in the real world?

Key Features:

• Rotations change the orientation (the direction it faces) of a figure.

• The image remains the same size and shape (congruent).

Direction:

Rotations turn in two directions: Clockwise (CW) or Counterclockwise (CCW).

Multiple Choice

The clock is going in the __________ direction.

• Clockwise

• Counterclockwise

Multiple Choice

The clock is going in the __________ direction.

• clockwise

• counter-clockwise

Degrees:

• In 8th Math, figures rotate in increments of 90 degree turns.

• 1 quadrant is 90 degrees.

• A full circle is 360 degrees.

Multiple Choice

How many degrees is a quadrant?

• 90 degrees

• 180 degrees

• 270 degrees

• 360 degrees

Multiple Choice

90 degrees is how many 90 degree turns?

• 1

• 2

• 3

• 4

Multiple Choice

180 degrees is how many 90 degree turns?

• 1

• 2

• 3

• 4

Multiple Choice

270 degrees is how many 90 degree turns?

• 1

• 2

• 3

• 4

Multiple Choice

What is the angle of rotation for this counter-clockwise rotation about the origin?

• 90°

• 180°

• 270°

• 360°

Center of Rotation:

The center of rotation is a designated point a figure will turn upon. In 8th Math, that point is the origin, (0, 0).

Multiple Choice

Triangle B is rotated 90° clockwise with the origin as the center of rotation to create a new figure. Which triangle shows the new location?

• A

• B

• C

• D

Multiple Choice

Identify the quadrant where the point is located. (10 , -5)

• I

• II

• III

• IV

Multiple Choice

True or False: 180 degrees clockwise = 180 degrees counter-clockwise

• True

• False

Multiple Choice

What does (x, y) --> (y, -x) mean?

• Switch the x and y coordinates and make the x-coordinate a negative number.

• Switch the x and y coordinates and change the sign of the x-coordinate.

Multiple Choice

True or False: 360 degree rotation = 0 degree rotation

• True

• False

Multiple Choice

A figure was transformed on a coordinate grid using the rule (x, y) ---> (-x, -y). Which of the following describes this transformation?

• A reflection across the x-axis

• A reflection across the y-axis

• A 90 degree clockwise rotation about the origin

• A 180 degree clockwise rotation about the origin

Multiple Choice

Rotate the point (5, 5) around the origin 180 degrees counterclockwise. State the image of the point.

Rule: (x, y) ---> (-x, -y)

• (5, -5)

• (5, 5)

• (-5, 5)

• (-5, -5)

Pay attention as you work through the problems with the teacher.

Time for Guided Practice . . .

Rotations, TEKS 8.10C (R)

Multiple Choice

I DO:

Triangle A is rotated 270° counterclockwise about the origin. Which rule describes rotating 270° counterclockwise?

• (x, y)→(y, -x)

• (x, y)→(x, y)

• (x, y)→(-y, x)

• (x, y)→(-x, -y)

Multiple Choice

WE DO:

Triangle A is rotated 270° clockwise with the origin as the center of rotation to create a new figure. Which triangle shows the new location?

• A

• B

• C

• D

Multiple Choice

YOU DO:

Triangle B is rotated 90° counterclockwise about the origin. Which rule describes this transformation?

• (x, y)→(y, -x)

• (x,y)→(x, y)

• (x, y)→(-x, -y)

• (x, y)→(-y, x)

​​Use your journal, lined paper, or dry erase board to practice solving the Quizizz problems on your own. Do as many problems as you can until the timer rings.

Time for Independent Practice . . .

Rotations, TEKS 8.10C (R)

Multiple Choice

How many degrees was the figure rotated?

• 90 degrees counterclockwise 

• 180 degrees

• 90 degrees clockwise

Multiple Choice

Triangle A is rotated counterclockwise 90° about the origin. Which triangle shows the image (new figure)?

• A

• B

• C

• D

Multiple Choice

How many degrees was the figure rotated?

• 90 degrees counterclockwise 

• 180 degrees

• 270 counterclockwise 

• 90 degrees clockwise

Multiple Choice

Triangle D is rotated 360° clockwise about the origin. Which rule describes this transformation?

• (x, y)→(-y, x)

• (x, y)→(-x, -y)

• (x, y)→(y, -x)

• (x, y)→(x, y)

Multiple Choice

Rotate the figure 180 degrees about the origin.

• A

• C

• B

• D

Multiple Choice

If you were to rotate ABCD 180°  about the origin, what would the coordinate of A' be?

• (-5, 5)

• (-3, -5)

• (-5, 3)

• (-3, 3)

Time for your Mastery Check:

It's time to assess your skills using a STAAR-related problem. Carefully select your answer to the next problem to test your knowledge. You will use this for your Self-Assessment.

Rotations, TEKS 8.10C (R)

Multiple Choice

Triangle A is rotated 270° counterclockwise with the origin as the center of rotation to create a new figure. Which rule describes rotating 270° counterclockwise?

• (x, y)→(y, -x) 

• (x, y)→(x, y)

• (x, y)→(-y, x)

• (x, y)→(-x, -y)

Poll

Self-Assessment:

• I'm an expert. I got this! (I can teach this skill to others.)

• I'm a Practitioner. I can do this with more practice. (I can re-do this lesson through Google Classroom.)

• I'm a Novice. I need help learning this skill! (I can come to tutoring to get the help I need, or I can ask an Expert for help.)