A boat leave a dock at noon and heads weat at a speed 25km/h. Another boat heads north at 20km/h and reaches the same dock at 1:00 pm. when were the boats closest to each other?

2. Homework Equations

when were the boats closest to each other?

3. The Attempt at a Solution

I use the pythagorean for the distance

but I'm not sure about how to sub them in?

I tried to assume that the second boat also leaves at noon, so the total distance will be 20km. But thats wrong. Please help, thanks =P[/b]