Similarity

Similarity

Monday Dec. 14, 2020

Multiple Choice

Warm - up: What are the important properties of dilations?

• Dilations change the sides and angles of the image

• Dilations preserve angle measures and all sides are scaled equally

• Only angles change

• One side can change without changing the others.

Multiple Choice

Dilation or distortion?

• Dilation

• Distortion

True or false? Be ready to defend your answer (only pick one)

• All equilateral triangles are similar

• All isosceles triangles are similar

• All right triangles are similar

• All circles are similar

Open Ended

Write your reasoning for your statement

A. All equilateral triangles are similar

B. All isosceles triangles are similar

C. All right triangles are similar

D. All circles are similar

The next two slides are purely informational

Please do not copy the answers to these, they are possible sample responses. Your reasoning is probably better and, more importantly, makes sense to you. Never copy an answer just to get a question right in this class, always write what makes sense to you and helps you learn.

Possible reasoning for A. All equilateral triangles are similar

Possible reasoning for B. All isosceles triangles are similar, C. All right triangles are similar, and D. All circles are similar

If you ever need to prove similarity...

One sure way to help prove that two shapes are similar is that there is a sequence of rigid motions (translation, rotation, reflection) that takes one shape over to the other so you can show your dilations.

We've been doing this with the shared center of dilation, where the triangles share a point and the sides are scaled from there.

Let's Practice Our Skills

There will be another slide deck for practice problems, that one will be graded as classwork