Departure point x-------------------------> East (Kyle speed 3 mi/h)
I
I
I
I
I
V
South
Tom ( Speed 5 Mi/h
Distance run by Tom after 4 h = 5x4 = 20 Mi,
Distance run by Kyle after 4 h = 3x4 = 12 Mi.
You will notice that from the sketch that x the Departure, East & South is a right triangle & the distance from both arrival is the hypotenuse > to calculate this distance let's apply Pythagoras :
(Hypotenuse)² = (20)² + (12)² ===>544 & Hypotenuse = √544 = 23.3 Mi