Question

The red figure is congruent to the blue figure. Which choice describes a sequence of transformations in which the blue figure is the image of the red figure? (In other words, try and map the red figure on the blue figure).

1. Rotate the triangle 90º counterclockwise about the origin and then translate it 10 units left and 9 units down.

2. Rotate the triangle 90º clockwise about the origin and then translate it 10 units left and 9 units down.

3. Rotate the triangle 90º counterclockwise about the origin then translate it 1 unit up.

4. Rotate the triangle 90º clockwise about the origin then translate it 1 unit up.

Answer 1

• 2. Rotate the triangle 90º clockwise about the origin and then translate it 10 units left and 9 units down.

Explanation:

• Easy way to take one of the vertices and apply the transformations

1. Rotate the triangle 90º counterclockwise about the origin and then translate it 10 units left and 9 units down.

• False

2. Rotate the triangle 90º clockwise about the origin and then translate it 10 units left and 9 units down.

• True
• (-3, 3) → (3, 3) → (3 - 10, 3 - 9) = (-7, -6)

3. Rotate the triangle 90º counterclockwise about the origin then translate it 1 unit up.

• False

4. Rotate the triangle 90º clockwise about the origin then translate it 1 unit up.

• False