Use the pythagorean theorem to solve this problem. william walks 3.0 miles south and then turns and walks 4.0 miles west. what is his displacement?

5.0 miles, southwest
12.0 miles, southwest
7.0 miles, southwest
1.0 mile, southwest

Since south and west are at 90 degree angle that means we can use pythagorean theorem to find the distance.

It goes like this:
c^2 = a^2 + b^2

a = 3
b = 4

implementing this in pythagoras formula we get that c = 5

answer is 5 miles southwest