Can someone give me the right answer,

Me complete this proof! prove that a quadrilateral is a square. me with the steps for this proof.

Koji is installing a rectangular window in an office building. the window is 823 feet wide and 534 feet high. the formula for the area of a rectangle is a=bh. what is the area of the window? enter your answer as a mixed number in simplest form in the box. $$ ft2

Answer! if you don’t mind, can you explain