Similarity of Triangles :
1. Shape of the triangles are same but not the sizes.
2. Corresponding Sides are proportionate.
3. All 3 corresponding angles are same.
4. Proven by AAA.
5. Similar triangles not necessarily overlap.
6. Area and perimeter of similar triangles needs not to be equal.
Congruency Of triangles ;
1. Shape and sizes of triangles are same.
2. Corresponding Sides are equal.
3. All 3 corresponding angles are same.
4. Proven by SAS, ASA, SSS, RHS.
The given figure shows triangles congruent to each other by 4 different criteria :
5. Congruent triangles overlap over each other.
6. Area and perimeter of congruent triangles are equal.
