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. 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.

2. 1.

   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
3. 2.

   Esme dilates a rocket sticker from the origin with scale factor 2/3. Corner D is at (6, 3), and the x row is 6 → 6 × 2/3. 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.

   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)

10. 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.

11. 7.

    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)
12. 8.

    Tala's leaf sticker is dilated from the origin: corner D(6, 3) went to D′(4, 2). In the x row, 6 → 4. What is the scale factor from old to new?

    2/3

13. 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.

14. 9.

    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

15. 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 6 | 2.

16. 10.

    Ari's car sticker is dilated from the origin: corner D(6, -9) went to D′(2, -3). In the x row, 6 → 2. What is the scale factor from old to new?

    1/3