Theorem: The diagonals of a parallelogram bisect each other. Kim is writing the proof of the theorem using two properties of a parallelogram as shown below. â€¢ The opposite sides of a parallelogram are parallel. â€¢ The opposite sides of a parallelogram are congruent. A parallelogram ABCD with diagonals AC and BD intersecting at G. Using the two given properties, Kim can prove that triangle AGB is congruent to triangle CGD using the _________ Postulate.
ASA postulate. angle DGC=angle AGB, angle DCA = angle CAB and DC=AB.