Question

Lauren made the plan shown for proving that quadrilateral ABCD with

Answer 1

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.