Answer:
Step-by-step explanation:
It is given that the quadrilateral ABCD has AB ≅ CD and BC ≅ DA is a parallelogram, then in order to prove opposite angles of the parallelogram are equal, we take ΔABC and ΔADC,
AC=AC(Common)
AB=CD(given)
BC=AD(given)
Thus, by SSS rule, ΔABC ≅ ΔADC
By CPCT, ∠B=∠C
Also, from ΔABD and ΔBCD, we have
AB=CD(given)
BC=AD(given)
BD=BD(common)
Thus, by SSS rule, ΔABD ≅ ΔBCD
By CPCT, ∠A=∠C
Since, opposite angles are equal,therefore ABCD is a parallelogram.
Draw in diagonals AC and BD. The given information and the shared side AC along with the Reflexive Property can be used to prove ΔABC ≅ ΔADC by the SSS Congruence Postulate. Using CPCTC, ∠B=∠C.The same can be done for ΔABD ≅ ΔBCD using the given information and the shared side BD. This will lead to ∠A=∠C. Therefore, ABCD is a parallelogram because opposite angles are congruent.
