Answers

2014-12-31T20:31:17+05:30
Consider a parellolgram ABCD ACD IS CONGRUENT BDC AS AD=BC,AC=BD,DC COMMON BASE SO THESE ARE CONGRUENT AND IN PARALLELOGRAM ADJACENT ANGLES SUM IS 180 SO ANGLE D=ANG C 
ANGLE C+D =180 THIS IMPLY THAT 
C=D ANGLE 
AS IN PARALLELOGRAM  ALL THE ANGLES ARE 90DEGREE SO IT IS A RECTANGLE
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