Which graph does not represent a function?

What is the length of the unknown leg in the right triangle ?

One line passes through (-7,-4) and (5,4) . another line passes through the point (-4,6) and (6,-9)

Marion has a bicycle that she is planning to take for a ride. the rim of the rear wheel lies 41 cm from the center of the wheel. the tire itself has a thickness of 3 cm. in order for marion to ride her bicycle 96,712 cm approximately how many rotations will the rear wheel make?