Make a right triangle using the two given points as two of the points.
One of the legs is 6 miles and the other leg is 5 miles.
The pythagorean theorem states that a² + b² = c².
a = 6 and b = 5.
6² + 5² = c²
Square 6 and 5.
36 + 25 = c²
Add the two together.
61 = c²
Find the square root of both. Since 61 is not a square number, leave it in radical form or you could approximate it. I gave it to the nearest hundredth.
= c OR 7.81 = c
Hope this helps!