rotations

Front

What is rotation in geometry?

Back

Rotation is a transformation that turns a figure around a fixed point, known as the center of rotation, by a certain angle in a specified direction.

Front

What is the center of rotation?

Back

The center of rotation is the fixed point around which a figure is rotated.

Front

What does a 90° counterclockwise rotation look like?

Back

A 90° counterclockwise rotation turns a figure to the left, moving each point to a position that is 90 degrees away from its original position.

Front

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

Back

The rule is (x,y) → (-y,x).

Front

What is the rule for rotating a point (x,y) 180°?

Back

The rule is (x,y) → (-x,-y).

Front

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

Back

The rule is (x,y) → (y,-x).

Front

How do you determine the angle of rotation?

Back

The angle of rotation is determined by how far the figure is turned around the center of rotation, measured in degrees.

Front

What is a clockwise rotation?

Back

A clockwise rotation turns a figure in the same direction as the hands of a clock.

Front

What is a counterclockwise rotation?

Back

A counterclockwise rotation turns a figure in the opposite direction of the hands of a clock.

Front

If a triangle is rotated 180° clockwise, what is the new position of its vertices?

Back

The new position of the vertices can be found by applying the rotation rule (x,y) → (-x,-y) to each vertex.