Which of the following sets contains multiples of six? {1, 6}

{2, 3}

{4, 9}

{12, 18}

Aconstruction worker needs to put a rectangular window in the side of a building he knows from measuring that the top and bottom of the window have a width of 8bfeet and the sides have a length of 15 feet he also measured one diagonal to be 17 feet what is the length of the other diagonal