Two triangles are congruent if any two sides/angles and the included angle/sides of one triangle is equal to any two sides/angles and the included angle/sides of the other triangle. Two triangles are congruent if the three sides of one triangle are equal to three sides of the other triangle. Two right triangles are congruent if the hypotenuse and a side of one triangle are equal to the hypotenuse and a side of the other triangle. The angles/sides opposite to equal sides/angles of a triangle are equal. Triangle inequalities and relation between 'angle and facing side' inequalities in triangles.
