Lesson Plan for SS 1.1 (50 minutes):

Target: I can compare measurements in similar figures.

8 minutes Warm-up: 10 minutes Classwork: Intro to new unit 1.1 Similarity p. 2 in packet10 minutes Add to Vocabulary to Tool Kit

similar figures, image, copy factor (%), perimeter, areaNote: Give students time to sketch examples and practice labeling with marks congruent sides and angles.

10 minutes Work with table group to complete p. 3 to measure the two figures.10 minutes Classwork: Review answers to make sure answers are accurate.2 minutes Reminders:

• Homework is a Zaption video on SS 1.2. Complete notes on pg. 4.• MathXL – 30 mins this week.

Quick Start Expectations1.Teaching Target: I can compare measurements in similar figures.2. Read over your new Learning Log for the new unit:

1) Complete Notes on pg. 4 of SS Inv. 1 packet by watching the Zaption Video Tour for SS 1.2 2) Math XL – 20 mins this week

3. Warm-up:1. What is the name of our next unit?

Stretching and Shrinking (SS) 2.

(Str

etch

to m

ake

odd

shap

es)

Drawing to scale isn’t just Stretching and Shrinking randomly. This unit will teach you how to draw to scale.

STRETCHING & SHRINKING UNITSS 1.1: An Introduction to Similarity

In this investigation, you will make scale drawings of figures.

Your scale drawings will have the same shape as the original figure, but may be larger or smaller.

The drawings will help you explore how some properties of a shape change when the shape is enlarged or reduced.

Inv. 1 packet p. 2

The Mystery Club at PI Middle School meets monthly. One day, a member announces that the school is having a contest. A teacher in disguise will appear for a few minutes at school each day for a week. Daphne manages to get a picture of the mystery teacher standing next to some magazines. She knows that the height of the PI Monthly magazine is 12 inches.

How do you think Daphne can use the PI Monthly magazine and picture to estimate the

teacher’s height?

The teacher advisor to the Mystery Club says that the picture is similar to the actual scene. What do you think the advisor means by similar? Is it different from saying that

two students in your class are similar?

The Mystery Club has a small flyer with their logo on it, but they want to make a large poster to attract new members. The large

poster will feature the club’s logo, “Super Sleuth,” in a larger size.

How does the general shape of the logo in the small flyer compare to the logo in the large poster?

The original and its image are similar figures.

original image

Use the class lab sheet:

original image

The general shapes of the two figures are the same.

Vocabulary Toolkit:

The figure that results from some transformation of a figure.

In mathematical terms, similar figures have the same shape but may have different sizes.

Work with your table group to complete the table with measurements and compare the two figures on LS 1.1

imageimageoriginal

original image

The lengths of the corresponding line segments are different. The image lengths are twice as long as the corresponding lengths in the original.

original image

The perimeters of the body and the hat in the image are twice as long as those in the original.

The perimeter, which is the sum of these doubled line segments, will also double.

original image

Doubling each side individually and then finding the perimeter is the same as finding the perimeter and then doubling it. This is the Distributive Property:

2ℓ+2ℓ+2w+2w=2(ℓ+ℓ+w+w)

original image

The angles in the image are the same as the corresponding angles in the original.

In mathematical terms, similar means that two figures have the same shape but may have different sizes.

The shapes of figures and their angle measures are the same.

Their side lengths, perimeters, and areas are different.

Reminders:• Homework is a Zaption video on SS

1.2. Complete notes on pg. 4.• MathXL – 30 mins this week.