Lesson 6Similarity
Learning Goal
Let’s explore similar figures.
Learning Targets
I can apply a sequence of transformations to one figure to get a similar figure.
I can use a sequence of transformations to explain why two figures are similar.
Lesson Terms
- similar
Warm Up: Equivalent Expressions
Problem 1
Use what you know about operations and their properties to write three expressions equivalent to the expression shown.
Activity 1: Similarity Transformations (Part 1)
Problem 1
Triangle
Print Version
Triangle
Problem 2
Hexagon
Print Version
Hexagon
Are you ready for more?
Problem 1
The same sequence of transformations takes Triangle
Activity 2: Similarity Transformations (Part 2)
Problem 1
Sketch figures similar to Figure A that use only the transformations listed to show similarity.
A translation and a reflection. Label your sketch Figure B.
Pause here so your teacher can review your work.A reflection and a dilation with scale factor greater than 1. Label your sketch Figure C.
A rotation and a reflection. Label your sketch Figure D.
A dilation with scale factor less than 1 and a translation. Label your sketch Figure E.
Activity 3: Methods for Translations and Dilations
Problem 1
Your teacher will give you a set of five cards and your partner a different set of five cards. Using only the cards you were given, find at least one way to show that triangle
Lesson Summary
Let’s show that triangle
Two figures are similar if one figure can be transformed into the other by a sequence of translations, rotations, reflections, and dilations. There are many correct sequences of transformations, but we only need to describe one to show that two figures are similar.
One way to get from
step 1: reflect across line
step 2: rotate
counterclockwise around step 3: dilate with center
and scale factor 2
Another way would be to dilate triangle