Find the missing variables quadrilaterals, please and thank you <3

Two variables, x and y, vary inversely, and x=12 when y=4. what is the value of y when x=3?

Simplify using positive exponents only.

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