1. Using the following real world example, elicit students prior knowledge to "Congruency":
- When the mechanical pencil runs out of lead, what do you look out for when choosing the refill?
- Possible suggestions from students would include shape and size.
- Pen these info on the board.
- Note: Others - correction tape; ball point pens
2. Based on the suggestions, draw out from students the common deciding factor: "Same Shape, Same Size".
3. Introduce the term "Congruent".
- That is, "Congruent" means "same shape, same size".
- The description of the word is only partial. Students will explore its mathematical meaning further in the next activity.
