1. Warm-Up
1. What is 1/3 of 3?
2. What is ¾ of 10?
3. What is ½ of 20?
4. What is ¼ of 20?

2. Essential Question
What is a transformation? How is the dilation
different from rotations, reflections, and
translations??

3. Warm-Up Quiz
1. What is the new ordered pair with a scale
factor of 4? (-4, 6)
2. Draw the coordinate plane and label the four
quadrants.
3. Plot the point (-3, 2)
4. Solve for x 4
x
5
20

4. Dilations Day 2
Unit 1, Day 12

5. Common Core GPS
MCC8. G. 3: Describe the effect of
dilations, translations, rotations, and
reflections on two-dimensional figures using
coordinates.

6. Language of the Standards
What is a…
Dilation?
Transformation?

7. Dilations
Let’s draw ΔPQR with vertices P (4, 4), Q (8, 0), and R (6, -2).
Dilate with a scale factor of ½ or 0.5.
Remember to take the coordinates and multiply by ½ or 0.5—
(x, y) becomes (1/2x, 1/2y).

8. Unit 1, Quiz 3
• Complete quiz and then…complete
the dilations task.

9. Work Session
Dilate each figure on the coordinate plane
with the given scale factor.

10. Give the scale factor of each dilated object.

11. 5. Triangle ABC is dilated with a scale factor of
4. If the coordinates of the vertices of ΔABC
are A(4, 8), B (12, 8), and C (16, 20), what are
the coordinates of the vertices of the image
after the dilation?

12. 6. Triangle RST has vertices R(3, 6), S(6, 3), and T (3, 3). Triangle
RST will be dilated by a scale factor of 1/3.
a. Find the coordinates of the vertices of the dilated
image, ΔR’S’T’.
b. On the coordinate plane below, graph ΔRST and ΔR’S’T’.

13. Closing
What questions/concerns do you have
about unit 1?