Two bikers bike4 miles north and 6 miles west. What is the shortest distance they must travel to get to their starting point?
Looks to me like this is a Pythagorean Theorem Problem (a^2 + b^2 = c^2). You are trying to find the hypotenuse, c. So you will actually use this formula instead: sqrt(a^2 + b^2) = c. Input 4 and 6 into a and b and voila!
Hope I could be helpful!