Two triangles are congruent if the three sides of the first are equal to the three corresponding sides of the second. The preceding is known as ________. 

If and only if two figures have the same shape and size, they are said to be congruent. When the corresponding sides of two figures of the same shape have the same length, the figures are said to be congruent.

SSS rule states that two triangles are congruent if all three sides of one triangle are equivalent to the corresponding three sides of the other triangle.