Lesson: Similar Figures, Dilations and Scale Factors

Similar Figures, Dilations and Scale Factor

Multiple Select

Which shapes are similar?

(Click on the two you think are similar)

• ABC

• FED

• IHG

Remember how we used to identify Similar Shapes.

BOTH CONDITIONS MUST APPLY.

​Similar Figures:

​To identify Similar Figures we must have:

• The Corresponding angles are equal

• The corresponding sides are proportional

Multiple Choice

The following triangles are Similar

• TRUE

• FALSE

Multiple Choice

Two objects that are the same shape but NOT the same size are _______.

• Congruent

• Vertical

• Similar

• Complementary

Moving To Dilations

Dilations happen When Similar Figures get enlarged or reduced

Multiple Select

choose the shapes that create a dilation.

(CHOOSE ALL THAT APPLY)

• Figure 1

• Figure 2

• Figure 3

• Figure 4

How do we get the Scale Factor?

Multiple Select

Find the scale factor of the dilation.

• $$\frac{8}{6}$$  

• $$\frac{3}{4}$$  

• $$\frac{6}{4.5}$$  

• $$\frac{6}{8}$$  

• $$1\frac{1}{3}$$  

Multiple Choice

Triangle ABC is dilated to produce triangle A'B'C' with scale factor 3/4 . Which describes the relationship between the two triangles?

• Triangle A'B'C' is an enlargement of triangle ABC

• Triangle A'B'C' is a reduction of triangle ABC

• Triangle A'B'C' is a mirror image of triangle ABC

Multiple Choice

A dilation always produces a similar figure. Similar figures have the same ______ but different ______. 

• measure; shapes
• sizes; shapes
• value; measures
• shape; sizes

Multiple Choice

The point (8, 12) was dilated to become point (2, 3). What was the scale factor?

• ½
• ¼
• 4
• 2

Multiple Choice

Dilate the figure by a scale factor of 3 with the origin as the center of dilation. What are the coordinates of the image?
A(3,3) B(6,6) C(9,3)

• A'(9,9) B'(18,18) C'(27,9)
• A'(6,6) B'(9,9) C'(12,6)
• A'(0,0) B'(3,3) C'(6,0)
• A'(1,1) B'(2,2) C'(3,1)