Math
posted by Barb .
Two boats leave a dock at the same time. One heads due east at 20 mph, and one heads due south at 15 mph. How far apart are the two boats after 45 minutes have elapsed?

I wonder if there is a current assiging one in someway?
Assuming not, in 3/4 hr
one is east 15 miles, and the other is S at 45/4 miles
How far apart?
distance=sqrt(15^2 + (45/4)^2 ) 
Please explain (45/4)^2. One boat is headed due east at 20 mph, and one heads due south at 15 mph