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Ch.3 - Justification and Similarity

Click here for Parent Guide with Extra Practice for Chapter 3  -  Justification and Similarity from CPM


Chapter

 Objective

Students will be able to…

Standard(s)

Help/Examples

 Practice

3.1.1

Perform a dilation of a given shape

G-SRT.1

Thinking about dilations


Dilating from an arbitrary point example

 Dilations

3.1.1

Understand dilations have equal angles and proportional corresponding side lengths

G-SRT.1

 Explore dilations

 

3.1.2

Understand a dilation as a transformation and (multiplying (and dividing) lengths of figures by a common number (zoom factor) produces a similar figure)

G-SRT.2

Prove two figures are similar after a dilation


Determine if two figures are similar using transformations and dilations

Determine a scale factor by applying ratios

 

3.1.3

Understand the ratio of the perimeter of similar figures is 1

G-SRT.2

Find a perimeter by using a scale factor and a proportion.


Find an area by using a scale factor and a proportion.

Perimeters of Similar Figures 

Areas of Similar Figures

3.1.3

Set up and solve proportional problems

G-SRT.2

 Find a length by using a scale factor and a proportion.


 

Solving similar triangles 1

Solving similar triangles 2

3.1.4

Apply proportional reasoning to real world situations

G-SRT.2

 

 

3.2.1

Use short cuts to prove similarity (SAS and AA)

G-SRT.2

Understand that similar triangles share angle measures and side ratios

Show triangle similarity using translation

Determine similarity by comparing angles


Similarity Statements

Side Lengths and angle measures in similar figures

 Similar Triangles

3.2.2

Prove Similarity using a flowchart (SAS and AA)

G-SRT.2

 

Prove that two triangles are similar by writing an algebraic proof

 

3.2.3

Understand that if the common ratio of corresponding sides of similar triangles is 1 then the triangles are congruent

G-SRT.4

G-SRT.5

 

 

3.2.4

Use short cuts to prove similarity (SSS)

G-SRT.2

 

 Similar Triangles 2

Similarity Rules for Triangles


3.2.5

Prove Similarity using a flowchart (SAS, AA, SSS)

G-SRT.2

 

 

3.2.6

Apply similarity to real world situations

G-SRT.4

 

 

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