Given: AD = BC and
Prove: DE congruent to CE

From concept of congruent triangles, DE ≅ CE can be proved.
Two triangles are said to be congruent if all three corresponding sides are equal and the values of all the three angles are also equal in measure. These triangles look identical in any orientation of rotation and if repositioned, they superimpose with each other.
In the given problem, considering triangles ΔADC and ΔBDC,
Therefore by (Side-Angle-Side axiom), triangles ΔADC and ΔBDC are congruent.
For any congruent triangles, any corresponding side of both the triangles are also congruent.
Thus DE ≅ CE (Proved)
Thus from the concept of congruent triangles, we prove the result that DE ≅ CE .
To learn more about congruent triangles , refer -
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