Class 7 Maths Congruence of Triangles | Introduction |

In geometry, two figures or objects are congruent if they have the same shape and size, or if one has the

same shape and size as the mirror image of the other.

Let us take five of spades from each of two identical decks of cards, they look exactly the same. We can

move one card and place it on top of the other one so that the pictures on the two cards coincide

exactly, as shown below:

Two objects like this is called congruent.

Two plane figures are called congruent if one figure can be moved so that it fits exactly on top of the

other figure.

Congruent figures have exactly the same shape and size, each part of one figure can be matched with a part of the other figure, and

- Matching angles have the same size,
- Matching intervals have the same length,
- Matching regions have the same area.

When two figures F_{1} and F_{2} are congruent, we write as F_{1} ≅ F_{2}

.