Question

Prove that diagonal of a parallogram are equal if and only if it is a rectangle

Answer 1

Answer:

in theoretically ,the sides of parallelogram would not be equal .it may different .but thre is one condition -the opposite sides of the parellelogram must be parellel and opposite angle also equal .

in such case ,there is no chance to be the diagonals become equal it occurs only in the case of a rectangle .

(the answer for this question is in the scert text of 9th )