Help with Opening PDF Files

## Chapter 17

### Part 1: For the problem in the Teacher's Edition, page 428

Provide students with the Problem Worksheet (PDF file).

Get books from the library containing pictures of animals with patterns on their bodies, such as butterflies, zebras, etc. Have the students bring in pictures of animals from magazines. Ask, Are the patterns on one side of the animals' bodies always a reflection of the other side, like on the ladybug? Find examples of animals where the pattern on one side of the animals' body is a reflection of the other side, and find other examples where the pattern on one side of the animals' body is not a reflection of the other side.

The pattern on one side of an animal's body is not always a reflection of the other side.

### Part 2: Be an Investigator

A good time to do this investigation is after Lesson 4 on symmetry.

### Materials

• rulers

#### Introducing the Investigation

Introduce the investigation by reading aloud the assignment at the top of the first page of the Description of Investigation and Student Report (PDF file), by having one of your students read aloud the assignment, or by having the students read the assignment individually.

Put the students in groups of two to work on the investigation.

#### Doing the Investigation

Make sure the students understand what it means to color in the design on one side of the line of symmetry so that geometric figures with a common edge do not have the same color on each side of the edge. You may need to demonstrate this by showing what it looks like when both sides of a common edge are colored the same color and when both sides of a common edge are colored different colors.

Display the designs that were created by the students in the classroom.