G'day

here is the question

Bobby and Kym are two hikers. Bobby walks at 3klms/h and kym walks at 4klm/h. bobby is exactly klm due west of kym. they start walking immediatley. bobby walks due east and kym walks due south. what is the shortest distance between the walkers?

okay so i thought that maybe i could make the equation

because i used pythagoras

cheers

D^{2}=(5-37)^{2}+(4t)^{2}

<3