# CBSE Class 7th Maths

## Congruence of Triangles

If two figures have exactly the same shape and size, then they are said to be congruent.
For congruence, we use the symbol ‘=’

Two plane figures are congruent, if each when superposed on the other covers it exactly.
e.g. F1 and F2 are congruent if the trace copy of F1 fits exactly on that F2. We can write this as F1 = F2

### Congruent Triangles

If all the sides and angles of a triangle are equal to the corresponding sides and angles of another triangle, then both the triangles are said to be congruent.

### SSS Criteria for Congruency

If under a given correspondence, the three sides of one triangle are equal to the three corresponding sides of another triangle, then the triangles are congruent.

### SAS Criteria for Congruency

If under a correspondence, two sides and the angle included between them of a triangle are equal to two corresponding sides and the angle included

### ASA Criteria for Congruency

If under a correspondence, two angles and the included side of a triangle are equal to two corresponding angles and the included side of another triangle, then the triangles are congruent.

### AAS Criteria for Congruency

AAS Rule: Triangles are congruent if two pairs of corresponding angles and a pair of opposite sides are equal in both triangles.