Question

Wayne is 12 mi due north of Jefferson, and Oakland is due west of Jefferson. Wayne is 28 mi from Oakland.

How far apart are Jefferson and Oakland?
Round your answer to the nearest tenth of a mile

Answer 1

This is a Pythagoras theorem problem. I have attached a diagram explaining what the question means. 

Now, using Pythagoras theorem,

$OW^2=WJ^2+OJ^2\\\\ OJ= \sqrt{OW^2-WJ^2}\\\\ OJ= \sqrt{28^2-12^2}\\\\ OJ= \sqrt{784-144}\\\\ OJ= \sqrt{640}\\\\ OJ= 8\sqrt{10}\ miles$

So, Jefferson is 8√10 miles from Oakland.