Stretching and Shrinking Study Guide for Unit Test

Click here to link to the Study Guide for the Stretching and Shrinking Unit Test.  The answers accompany the documents.

Strectching and Shrinking Study Guide

Some reference guides from Math on Call.


Click here to access the 2015 Stretching and Shrinking Study Guide.

Today's Check-in on Scale Factor and Ratios.
Click here to find today's check-in.  This focuses on the following essential questions:
1. Can you find the scale factor given to similar shapes?
2. Can you find an unknown side length when given similar shapes?
3. Can you provide the relationship of scale factor to perimeter between two similar shapes?
4. Can you provide the relationship of scale factor to area between two similar shapes?

Similar Triangle Review Sheet

Attached here is a great review sheet for similar triangles.  
Click here to access.

On it are questions posed around:

• Scale Factor
• How to tell if two figures are similar
• How side lengths change with scale factor
• How area changes with scale factor.

Please check your understanding and come to Mr. Hagerty and Mr. Cuthbert with any questions.

Extension Project for Stretching and Shrinking

When you complete your normal homework you can start the following project using the computer program Google Sketch-up.

You may have to install this from your Self Service.

Here is the introductory lesson

Click here to access

Here is a more challenging lesson.  

Click here to access

Investiagtion 2.1 Mug Wump!

Students are currently graphing Mug Wump and his impostors on coordinate graphs.  They are investigating how a "rule" will change the dimensions of an original shape.  Some rules will allow the shapes to be similar and some will not.  

Do you have any ideas which rules will change an image to be similar?

Use the following link to help you in plotting points on a coordinate graph.

Click here to access.

Students creating rubber band stretchers.

Students used rubber bands to make scaled sketches in the first investigation.

Here are some pictures of them working. 

Stretching and Shrinking Unit #3

Common Core Standards for this Unit:

• 7.RP.A.2 Recognize and represent proportional relationships between quantities.
• 7.RP.A.2a Decide whether two quantities are in a proportional relationship, e.g., by testing for equivalent ratios in a table or graphing on a coordinate plane and observing whether the graph is a straight line through the origin.
• 7.RP.A.2b Identify the constant of proportionality (unit rate) in tables, graphs, equations, diagrams, and verbal descriptions of proportional relationships.
• 7.RP.A.3 Use proportional relationships to solve multistep ratio and percent problems.

Goals for this Unit:

• Similar Figures Understand what it means for figures to be similar

- Identify similar figures by comparing corresponding sides and angles

- Use scale factors and ratios to describe relationships among the side lengths, perimeters, and areas of similar figures          

- Use algebraic rules to produce similar figures

- Recognize when a rule shrinks or enlarges a figure

• Reasoning With Similar Figures Develop strategies for using similar figures to solve problems

- Predict the ways that stretching or shrinking a figure will affect side lengths, angle measures, perimeters, and areas

- Use scale factors or ratios to find missing side lengths in a pair of similar figures

- Use similarity to solve real-world problems