Rotations on a Coordinate Plane

Rotations on a Coordinate Plane

Jojie Madronado

01/15/2021

Objectives : The students can:

• Identify rotations in the plane.

• Apply rotation formulas to figures on the coordinate plane.

Rotation

A transformation in which a figure is turned about a fixed point, called the center of rotation.

Rotation

Rays drawn from the center of rotation to a point and its image form an angle called the angle of rotation

Open Ended

Is translation an Isometry?

Rotation is an Isometry

Segment lengths are preserved.

Angle measures are preserved.

Parallel lines remain parallel.

Orientation is unchanged.

Direction of Rotations

Clockwise Rotation is positive also written as CW

Counterclockwise rotation is negative also written as CCW

Multiple Choice

Rotate the point (7,8) around the origin 90 degrees counterclockwise.
State the image of the point.

• (-7,-8)
• (8,-7)
• (-8,7)
• (8,7)

Multiple Choice

What are the coordinates of R' if R is rotated 180° counterclockwise about the origin, and R is the point (-1, -5)?

• (1, 5)
• (1, -5)
• (-1, 5)
• (5, 1)

Multiple Choice

If you were to rotate ABCD 90° counterclockwise about the origin, what would the coordinate of A' be?

• (-5, 5)

• (-3, 5)

• (-5, 3)

• (-3, 3)

Multiple Choice

If you were to rotate ABCD 90° counterclockwise about the origin, what would the coordinate of A' be?

• (-5, 5)

• (-3, 5)

• (-5, 3)

• (-3, 3)

Multiple Choice

Problem 8: Find D' after D is rotated 180° counterclockwise.

• (7,−1)

• (1,−2)

• (2,−1)

• (−2,−1)

Multiple Choice

Problem 5: Find A' after A is rotated 180° counterclockwise.

• (2,−7)

• (−2,−7)

• (−7,2)

• (2,1)

Multiple Choice

Problem 3: Find C' after C is rotated 180° clockwise.

• (7,−1)

• (7,−7)

• (−7,−1)

• (2,1)

Multiple Choice

Counter clockwise (CCW) is a _________________ direction while clockwise (CW) is a _________________ direction.

• positive; negative

• negative; positive

• negative; negative

• positive; positive

Multiple Choice

What's the degree of rotation in this image?

• 90 degrees

• 180 degrees

• 270 degrees

• 360 degrees

Multiple Choice

What's the degree of rotation in this image?

• 90 degrees

• 180 degrees

• 270 degrees

• 360 degrees

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)

Multiple Select

Match the description with the graph shown below. (Hint: There are two correct answers)

• $90\degree\ clockwise\ rotation$

• $90\degree\ counterclockwise\ rotation$

• $270\degree\ clockwise\ rotation$

• $270\degree\ counterclockwise\ rotation$

Multiple Choice

Problem 6: Find B' after B is rotated 270° counterclockwise.

• (7,−7)

• (7,−2)

• (−7,7)

• (2,1)

Poll

Did you understand our lesson today?

• Yes

• No

Open Ended

Exit Ticket : 3-2 1

Three things I learned today?

Two ways I contributed today.

One question I still have ..

Thank you.

Jojie Madronado