INTRODUCTION

Introduction :

The relation of two objects being congruent is called congruence.

If two angles have the same measure, they are congruent. Also if two angles are congruent, their measure are same.

Congruent objects are exact copies of one another.

The method of superposition examines the congruence of plane figures.

Two plane figure, say, F₁ and F₂ are congruent if the trace – copy of F₁ fits exactly on that of F₂. We write this as F_{1 ≅} F₂.

Two line segments, say AB and CD, are congruent if they have equal lengths. We write this as AB @ However, in practice, it is common to write it as AB = CD.

Two angles , say, ∠ABC and ∠PQR, or as m∠PQR = m∠ABC, are congruent if their measures are equal. We write this as ∠ABC @ ∠PQR or as m∠PQR = m∠A  .

However, in practice, it is common to write it as  ∠PQR = ∠ABC.