Triangles and other geometric figures that can be placed exactly on top of one another are considered congruent. For triangles to be congruent, their corresponding sides and angles must be equal - if the three sides of one triangle are equal to another, or if one side and the two angles of one triangle match another, the triangles are congruent. Congruency requires equality of both sides and angles between figures.

3. Triangles , rectangles , circles
and such other geometric
figures which can be placed
one over the other to fit exactly
are called congruent figures

4. Congruency
If two triangles are congruent,
then the sides and angles of
one are equal to the sides and
angles of the other, angles
opposite to equal sides are
equal and sides opposite to
equal angles are equal.

5. If the three sides of a triangle are
equal to the three sides of another
triangle, then these triangles are
congruent

6. Two sides and one angle
If two sides of a triangle and their included
angle are equal to two sides of another triangle
and their included angle, then these triangles
are congruent

7. One side and two angles
If one side and the two angles on it of a
triangle are equal to one side and the two angles
on it of another triangle, then the two triangles
are congruent.