Rotations and Dilations.

Front

What is a rotation in geometry?

Back

A rotation is a transformation that turns a figure around a fixed point, called the center of rotation, by a certain angle in a specific direction.

Tags

CCSS.8.G.A.3

CCSS.HSG.CO.A.5

Front

What are the coordinates of a point A(x, y) after a 90° counterclockwise rotation?

Back

The new coordinates will be A'(-y, x).

Tags

CCSS.8.G.A.3

CCSS.HSG.CO.A.5

Front

What are the coordinates of a point A(x, y) after a 180° rotation?

Back

The new coordinates will be A'(-x, -y).

Tags

CCSS.8.G.A.3

CCSS.HSG.CO.A.5

Front

What are the coordinates of a point A(x, y) after a 270° counterclockwise rotation?

Back

The new coordinates will be A'(y, -x).

Tags

CCSS.8.G.A.3

CCSS.HSG.CO.A.5

Front

What is dilation in geometry?

Back

Dilation is a transformation that changes the size of a figure but not its shape, using a scale factor.

Tags

CCSS.8.G.A.3

Front

What does a scale factor greater than 1 indicate in dilation?

Back

It indicates that the figure will enlarge.

Tags

CCSS.8.G.A.3

Front

What does a scale factor less than 1 indicate in dilation?

Back

It indicates that the figure will reduce in size.

Tags

CCSS.8.G.A.3

Front

If a figure is dilated by a scale factor of 2, what happens to the coordinates of point A(3, 4)?

Back

The new coordinates will be A'(6, 8).

Tags

CCSS.8.G.A.3

Front

What is the center of dilation?

Back

The center of dilation is the fixed point in the plane about which all points are expanded or contracted.

Tags

CCSS.8.G.A.3

Front

How do you find the coordinates of a point after dilation?

Back

Multiply each coordinate of the point by the scale factor.

Tags

CCSS.8.G.A.3