## CHAPTER 5: 2D GEOMETRY

**Lesson 1: Lines of Symmetry **

Use these interactive activities to encourage students to have fun on the Web while learning about 2D geometry. Students can try these activities on their own or in pairs.

**Goal**

Identify lines of symmetry by folding shapes.

**Builds Upon**

Student Book pages 144-146

**Instructions for Use**

**Reflection Symmetry ** allows students to test the symmetry of a variety of shapes.

To use Reflection Symmetry, click on “Reflection Symmetry”. Read through each question and investigate what each shape would look like if folded or reflected in a mirror by clicking on “Fold” or “Play” under each shape. Try to predict the answer before you do it. Read each question and work out the answer on a piece of paper before clicking “Show” under the figure to get the answer. When you have completed the first page, click on “Next” at the bottom of the page to continue onto the next screen. Complete the two questions on this screen. If you want to go back to the previous screen, click on “Previous” at the bottom of the page.

**More About Symmetry ** allows students to place lines of symmetry on various shapes.

To use More About Symmetry, read the instructions and then click on “recording sheet” on the third line to print out the recording sheet for the activity. Click on “Vertical” or Horizontal” and then click “New Figure”. Place your mouse cursor on the line that you see in the box – it will be on the left-hand side if you chose “Vertical” or at the top of the screen if you chose “Horizontal”. Drag the line to a place on the figure where you think it will make a line of symmetry. If you are correct, you will see a positive message on the screen. If not, you can move the line again.

After you have practiced on some vertical and horizontal figures, click on “Any”. Try to find the lines for eight more figures, keeping a record in the table on the recording sheet. Sometimes the line of symmetry will be horizontal, vertical or both. Write V for a vertical line or H for a horizontal line. If you are correct on the first try, write yes in the second line of the table and if not, write no. In the third line, write the number of tries you needed to place the line correctly.