Identifying congruent shapes

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Polygons are congruent if they are the same size and shape that is, if their corresponding angles and sides are equal. The activity helps in identifying congruent shapes.


  • Identify congruent shapes
  • Understand shape and size

Estimated Time

30 minutes

Prerequisites/Instructions, prior preparations, if any

Prior knowledge of point, lines, angles, parallel lines, closed figures

Materials/ Resources needed

  1. Digital : Computer, geogebra application, projector.
  2. Non digital : Worksheet and pencil
  3. Image files :
    1. Congruence class image1.jpeg
    2. Congruence class image2.jpeg
    3. Congruence class image3.gif
    4. “Congruence class image4.jpeg”

Process (How to do the activity)

  • Use the image files to illustrate
  • How many things do you see that are same
  • Point out the things that are same.
    1. Things that are same but different in colour
    2. Things that are same but different in size
    3. Things that are same that are same shape and size
  • Point out different shapes that are formed with existing shapes
  • HW: Observe regarding shapes
    • If two figures are the same shape, are they the same size?
    • If two figures are the same size, are they the same shape?

Evaluation at the end of the activity

  • Students should be able to identify same shapes that are of different sizes.
  • Students should be able to understand that different shapes can have same size
  • The teacher can ask students to think of many objects which are mass-produced and that are found to be exactly the same size and shape like pens, CD-roms, cars etc.