When stating that two triangles are congruent, use a congruence statement. The order of the letters is very important, as corresponding parts must be written in the same order. Notice that the congruent sides also line up within the congruence statement. For example when we write triangle ABC congruent to triangle PQR , angle A is congruent to angle P , angle B is congruent to angle Q, angle C is congruent to angle R. hope you got how to write a congruence equation. For more details on different congruent rules , their definitions and explanations refer Byju's