Does It Match?

Cindy Jacobs

Description

This lesson allows students to identify lines of symmetry of given figures such as shapes, letters, and objects.

Objectives

The student knows symmetry, congruency, and reflections in geometric figures using concrete materials (for example, pattern blocks, geoboards, mirrors).

Materials

-Scissors
-Construction Paper Cut In Half (enough for each student to have two halves)
-Chalk
-Notebook or Handwriting Paper
-Liquid Non Toxic Paint
-Paint Containers
-Plastic Spoons (one per paint container)

Preparations

1. Gather materials needed for the lesson.
2. Have liquid paint accessible for students with plastic spoons for dipping.

Procedures

1. Introduce the term symmetric. Explain that symmetric figures have two parts that match when folded. The fold line is the line of symmetry.

2. Give students one half a sheet of construction paper (save the other half for later). Tell them to fold their paper in half. Have them cut out one half of a heart. Then have them unfold it so they can see the matching half. Explain that this line is the line of symmetry. Have students fold their hearts in half making a horizontal fold line. Explain why this new fold would not be a line of symmetry (the parts don't match).

3. Print the first 14 letters of the alphabet A through N on the chalkboard. Be careful with how you print the letter C. Make sure that you print it so the top and bottom are symmetrical. With student assistance, determine which letters have a line of symmetry (Answers: A,B,C,D,E,H,I,M). Draw a line of symmetry on each letter that is determined to have one. Cross out the letters (non examples) which do not have a line of symmetry.

4. Next, ask students if they think an object could have more than one line of symmetry? (Answer: Yes) Draw a rectangle on the chalkboard. Ask them how many lines of symmetry a rectangle has? (Answer: Two, one vertical and one horizontal). You may want to have a student volunteer draw the lines of symmetry on the rectangle. Draw a square on the chalkboard. Ask students how many lines of symmetry a square has? (Answer: Four, one horizontally, one vertically, two diagonally) You may want to have student volunteers draw these lines of symmetry as well.

5. Pass out notebook or handwriting paper to students. Print the remaining letters of the alphabet O through Z on the chalkboard. Have students print these letters on their paper. Instruct them to identify and draw the line of symmetry on each letter that has one (Answers: O,T,U,V,W,X,Y). They are to cross out letters (non examples) that don't.

6. Collect these papers for assessment purposes. Go over the answers by identifying the lines of symmetry for letters O through Z on the chalkboard. Draw the lines of symmetry. Clarify any misunderstandings that students may have.

7. As a culminating activity, tell students that we are going to make Symmetric Art. Pass out the remaining half sheets of construction paper to students. Have liquid paint available for student use. Instruct students to place a small blob of paint in the center of each paper and fold the paper in half. When papers are unfolded, they should have a symmetrical work of art. You may want to use these as a bulletin board display titled -Symmetry-.

Assessments

1. Mastery and non mastery will be informally based on student participation and feedback while identifying and drawing lines of symmetry.
2. For the remaining 12 letters of the alphabet, students should identify at least 6 out of the 7 letters that have a line of symmetry to demonstrate mastery or non mastery of symmetry.

Extensions

1. You may wish to give students geometric shapes to trace, cut, and locate lines of symmetry. Students could also be given assorted pre- cut shapes from dies to determine symmetry, and then prove to others which ones are symmetrical.
2. You may want to give students half a picture cut from a magazine and have him or her make it symmetrical by completing the missing half. 3. For a Valentine's Day activity, students can make Valentine Cards by folding construction paper on a line of symmetry and adding hearts.