Beacon Lesson Plan Library

Congruent and Similar Figures

Melissa Aldridge


This learning activity introduces students to the concept of congruent and similar figures. The class will identify, classify, and describe the similarities and differences among these figures.


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


-Two small balls
-Two large balls
-Styrofoam figures
-Blunt-tipped scissors
-Five baggies containing paper clips
-Chart paper


Gather materials such as newspapers, magazines, styrofoam balls, scissors, magazine clippings of congruent and similar objects, and definitions of terms.


1. Gain the students' attention by tossing two small balls and two large balls to four different students.

2. Ask the students to brainstorm ideas about the similarities and differences among the four balls. Record responses on chart paper.

3. Define the terms congruent and similar while displaying styrofoam figure examples of each. Hold up two pictures cut out from a newspaper or magazine. Ask the students to record their answer of either congruent or similar on their paper. Give the correct answer when every student has recorded his or her answer.

4. Divide the class into groups of four or five. Give each group a plastic baggie containing figures to classify, one congruent label, and one similar label. Instruct the students to classify figures underneath one of these two headings. After all the figures have been sorted, allow groups a few minutes to rotate in order to check each group's answers.

5. Distribute magazines and newspapers for students to select two sets of congruent figures and two sets of similar figures. Students should identify figures as congruent or similar by placing a -C- or -S- on the pictures and connecting them with a paper clip.

6. Have students share their findings with others in their groups.


Teacher will assess this activity through student observation and asking students to write a paragraph explaining what a congruent figures are and what similar figures are.


Allow students time, perhaps during center time, to create clay models of congruent and similar figures.
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