Rotations and Reflections

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 specified angle in a specified direction.

Front

What is the rule for rotating a point (x,y) 90° counterclockwise?

Back

(x,y) → (-y,x)

Front

What is the rule for rotating a point (x,y) 270° counterclockwise?

Back

(x,y) → (y,-x)

Front

What is a reflection in geometry?

Back

A reflection is a transformation that flips a figure over a line, creating a mirror image.

Front

What is the rule for reflecting a point (x,y) over the x-axis?

Back

(x,y) → (x,-y)

Front

What is the rule for reflecting a point (x,y) over the y-axis?

Back

(x,y) → (-x,y)

Front

What happens to the coordinates of a point when it is reflected over the line y=x?

Back

(x,y) → (y,x)

Front

What is the difference between rotation and reflection?

Back

Rotation turns a figure around a point, while reflection flips a figure over a line.

Front

If triangle A has vertices A(2,3), B(4,5), and C(6,7), what are the coordinates after a reflection over the x-axis?

Back

A'(2,-3), B'(4,-5), C'(6,-7)

Front

What is the angle of rotation for a 180° rotation?

Back

A 180° rotation turns a figure halfway around the center of rotation.