Concepts

Rotation: The motion of a rigid object around a fixed point.

Rules

To rotate an object around a fixed point:

1. Determine if the movement will be clockwise (negative) or counter-clockwise (positive).
2. Starting at the fixed point the object will be rotating around, find the two lines that connect to that point.
3. Choose one of the lines to rotate first. Move that line in the clockwise or counter-clockwise direction until it has completely rotated around the point in the number of degrees required. Draw the line (with the same length) in the new location.
4. Choose the second line to rotate next. Move that line in the clockwise or counter-clockwise direction until it has completely rotated around the point in the number of degrees required. Draw the line (with the same length) in the new location.
5. Draw the rest of the lines needed to complete the shape. 

Example

Graph the image of ∆CDE after rotation 270° counter- clockwise around the point D.

Solution

To rotate the object around point D:

1. Determine if the movement will be clockwise (right) or counter-clockwise (left). (In this case, the movement is counterclockwise.)
2. Starting at point D (the point the object will be rotating around), find the two lines that connect to that point. (In this case, lines DC and DE).
3. Rotate line DC first. Move that line in a counter-clockwise direction until it has rotated around point D 270°. Draw the line with the same length (3 units) in the new location.
4. Rotate line DE next. Move that line in a counter-clockwise direction until it has rotated around point D 270°. Draw the line with the same length (6 units) in the new location.
5. Draw line EC to complete the shape.

Prerequisite Skills

Graph Points on Coordinate Plane (4.11.2)