Use the image to determine the direction and angle of rotation.

Graph of polygon ABCD in quadrant 2 with point A at negative 7 comma 5. A second polygon A prime B prime C prime D prime in quadrant 1 with point A prime at 5 comma 7.
270° clockwise rotation
270° counterclockwise rotation
90° counterclockwise rotation
180° clockwise rotation

1 answer

To determine the direction and angle of rotation from polygon ABCD to polygon A'B'C'D', we can analyze the coordinates of the points provided.

  • Point A is at (-7, 5) and point A' is at (5, 7).

For a rotation, we typically use the origin (0, 0) as the center of rotation.

Let's consider a 90° or 270° rotation:

  1. 90° counterclockwise rotation:

    • The formula for a point (x, y) undergoing a 90° counterclockwise rotation is (-y, x).
    • Applying this to point A: \[ A(-7, 5) \rightarrow A'(y, -x) = (-5, -7) \]
    • This does not match A' (5, 7).
  2. 90° clockwise rotation:

    • Using the formula for a 90° clockwise rotation, which is (y, -x): \[ A(-7, 5) \rightarrow A'(y, -x) = (5, 7) \]
    • This does match A' (5, 7).

Thus, the rotation that transforms A to A' is a 90° clockwise rotation.

Now let's consider the remaining options mentioned in your list:

  • 180° rotation: This would swap the coordinates and change their signs: \[ A(-7, 5) \rightarrow A' (7, -5) \] This does not match.

  • 270° clockwise rotation: This is equivalent to 90° counterclockwise, which we already checked and found does not match.

  • 270° counterclockwise rotation: This would be equivalent to a 90° clockwise rotation, which we found does match.

Final determination:

  • The correct answer is 90° clockwise rotation.