Beacon Lesson Plan Library

Figure This

Alice Bobe
Bay District Schools


In this activity, students identify congruent figures and match shapes using transformation.


The student understands the concepts of spatial relationships, symmetry, reflections, congruency, and similarity.

The student predicts, illustrates, and verifies which figures could result from a flip, slide, or turn of a given figure.


- A door mirror
- Paper, pencils, and scissors for each student
- Templates of five shapes for each student
- Graph paper
- Board to write on with markers and eraser


1. Prepare five different shape templates for each student, for example: a star, triangle, hexagon, rectangle and pentagon
2. Gather graph paper
3. Obtain door mirror
4. Obtain board to write on with markers


1. In a large group setting explain and show using a door mirror how you see your movement in a mirror. Talk about how the image is opposite of what you are doing when looking in a mirror.

2. Divide the class into pairs. Explain that one student is to move slowly one body part while the other partner mirrors the movement. Each student takes turns in leading the movement. Walk around and observe students. Sample question to ask students: - Which arm do you move when your partner's right arm moves?- (left arm)

3. Introduce and write the word -congruent- on the board and discuss meaning. (They have exactly the same size and shape.) Write the agreed-upon definition on the board.

4. Give out five different shape templates, for example: a star, triangle, hexagon, rectangle and pentagon for the students to copy on a sheet of paper using a pencil. Then, ask the students to carefully cut out their shapes.

5. Students return to their partner and match the congruent figures.

6. Students return to the large group and discuss what they learned about matching the figures. Introduce and discuss -transformation- (the change of position of a figure). Write this word and its definition on the board. Ask the students to copy both terms and their definitions on their paper.

7. Ask the students to trace one of their shape templates on their paper and beside it trace it again in a different direction. Notice that the size and shape did not change. The shape is still the same, congruent.

8. Ask the students to choose a shape and trace it once. Then slide it over, up, or down at least two spaces on the graph paper and trace it again.

9. Ask, -Did it change?- Discuss possible answers.

10. Ask the students to flip and turn their shape and see what happens. Discuss possible answers.

11. Ask the students to complete the worksheet on congruence (see attached file).


Assess the worksheet for accuracy in order to check understanding of congruence and transformation. Students scoring below a predetermined level can be given alternate work before redoing a similar assessment.


Students with exceptionalities or varying learning styles may have a partner and/or work in a small group.
Ask the students to design a border on a letterhead that shows congruence and transformation. Ex.

Attached Files

A worksheet to help with assessment of the lesson.     File Extension: pdf

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