A construction worker needs to put a rectangular window in the side of abuilding. He knows from measuring that the top and bottom of the windowhave a width of 9 feet and the sides have a length of 12 feet. He alsomeasured one diagonal to be 15 feet. What is the length of the otherdiagonal?A. 12 feetB. 15 feetC. 21 feetD. 9 feet