Enlarge and shrink from the origin with any scale factor

Answer Key - Grade 8 Math Worksheet - Building Confidence

Circle the best answer, or write your answer on the line.

1. 1.

   Ari dilates a kite sticker from the origin with scale factor 3/2. Corner D is at (4, 2), and the x row is 4 → 4 × 3/2. What is the x-coordinate of D′?

   6

2. Read this first

   Use this

   Coordinate grid, all four quadrants, each square one unit, 20 squares across (−10 to 10), origin in the middle. The boat sticker with corner D(3, 6) marked; the image is not drawn. Table old | new: the x row 3 | 3 × 4/3.

3. 2.

   Bo dilates a boat sticker from the origin with scale factor 4/3. Corner D is at (3, 6), and the x row is 3 → 3 × 4/3. What is the x-coordinate of D′?

   4
4. 3.

   Jun dilates a star sticker from the origin with scale factor 3/4. Corner D is at (8, 4), and the y row is 4 → 4 × 3/4. What is the y-coordinate of D′?

   3

5. Use this

   The butterfly sticker with corner D(-4, 2) marked; the image is not drawn. Table old | new: the y row 2 | 2 × 3/2.

6. 4.

   Kira dilates a butterfly sticker from the origin with scale factor 3/2. Corner D is at (-4, 2), and the y row is 2 → 2 × 3/2. What is the y-coordinate of D′?

   3

7. Use this

   Coordinate grid, all four quadrants, each square one unit, 20 squares across (−10 to 10), origin in the middle. The robot picture is drawn; the image is not drawn. Table old (x, y) | new (x, y): C(2, 4) | C′(3, 6); F(4, 2) | F′(6, 3); G(6, 4) | ?

8. 5.

   Luz dilates a robot picture from the origin with scale factor 3/2. The table shows corners C and F done. Corner G is at (6, 4). Where is G′? Write it like (7, -3).

   (9, 6)
9. 6.

   Milo dilates a castle picture from the origin with scale factor 2/3. The table shows corners C and F done. Corner G is at (6, -9). Where is G′? Write it like (7, -3).

   (4, -6)
10. 7.

    Noah dilates a bus picture from the origin with scale factor 4/3. The table shows corners C and F done. Corner G is at (-3, 6). Where is G′? Write it like (7, -3).

    (-4, 8)

11. Use this

    Coordinate grid, all four quadrants, each square one unit, 20 squares across (-10 to 10), origin in the middle. The tent picture is drawn; the image is not drawn.

12. 8.

    Pia dilates a tent picture from the origin with scale factor 3/4. The table shows corners C and F done. Corner G is at (-8, 4). Where is G′? Write it like (7, -3).

    (-6, 3)
13. 9.

    Ren's kite sticker is dilated from the origin: corner D(4, -4) went to D′(6, -6). In the x row, 4 → 6. What is the scale factor from old to new?

    3/2

14. Use this

    Coordinate grid, all four quadrants, each square one unit, 20 squares across (−10 to 10), origin in the middle. The sticker and its image are both drawn, with D and D′ labeled. Table old | new: the x row 8 | 10.

15. 10.

    Zee's snowflake sticker is dilated from the origin: corner D(8, 4) went to D′(10, 5). In the x row, 8 → 10. What is the scale factor from old to new?

    5/4