New Seats! Intro to Stretching and Shrinking

› Mathematical Highlights› Corresponding sides and angles

Work on tonight’s homework› Pizzazz Worksheet page 130

How can you judge whether two objects are similar?

They look alike and have the same shape.

You probably use the word similar quite a bit in everyday conversation. For example, you might say that one song sounds similar to another song or that your friend’s bike is similar to yours.

Similar is also a mathematical word, which is used to describe a type of relationship between shapes.

Recognize similar figures visually and identify that figures are similar by comparing sides and angles.

Understand and use the equivalence of ratios of sides to examine similar figures and find unknown lengths.

Understand the relationship between measures of lengths in figures and the scale factor relating two similar figures.

Use the scale factor between figures to scale a figure up or down and to predict the lengths of corresponding edges and areas.

Use the concept of similarity to solve everyday problems.

WEEK 1: Quarter 2

Find a pair of corresponding parts.

1.Side CA

2.Side CB

3.Angle D

4.Angle E

Please have your homework on your desk and get started on your warm up.

Correct Pizzazz p. 130 Investigation 1:Enlarging Figures

› 1.1 Stretching a figure (first test) Tonight’s homework

› Pizzazz worksheet p. 131

In this investigation, you will use rubber bands to make enlargements of drawings. Although this is not a precise way to enlarge drawings, it’s fun- and you can see some interesting relationships between a figure and its enlarged image.

As you work on this investigation, think about these two questions:

When a figure is enlarged, which of its features remain the same?

When a figure is enlarged, which of its features change?

Michelle, Daphne, and Max are the officers of their school’s Mystery Book Club. Max designed a flyer inviting new members to attend the club’s next meeting. (Read the flyer.)

Daphne thought it would be a good idea to make a large poster announcing the meeting. She wanted to use the detective figure from the flyer, but at a larger size. Michelle showed her a clever way to enlarge the figure by using rubber bands.

Use your stretcher to enlarge the figures on Labsheets1.1 and 1.2

WEEK 1: Quarter 2

Find a pair of corresponding parts

1. Side RH

2. Side OL

3. Define ratio

4. Define scale factor

Please have your homework on your desk and get started on your warm up.

Correct last night’s homework Work on

› Problem 1.1 (answer in your journal) Homework

› Follow up 1.1

Compare the following objects

WEEK 1: Quarter 2

Please have your homework on your desk and complete the warm up.

Discuss Follow up 1.1. Please write down any answers that you do not have filled in.

Class Activity: 3 band stretcher with partners

Discuss Area of a circle Tonight’s assignment

› Core Workbook p. 355 - 356

Area

Radius

CenterDiameter

Circumference

The diameter d is twice the radius r.

dd = 2= 2rr

Remember!Pi () is an irrational number that is often

approximated by the rational numbers 3.14

and .227

Welcome to Pre-Algebra Honors!Friday

• Please have last night’s homework on your desk and your weekly assignment sheet.

• Correct core workbook p. 355 – 356

• Get started on Application 1– What you do not finish is

homework