Answer
$6.71$ miles (approximately)
Work Step by Step
Apply Pythagorean theorem.
$c^2=a^2+b^2$
Plug $a=6$ miles and $b= 3$ miles.
We have $c^2=6^2+3^2=36+9$
or, $c^2=45$
or, $c=\sqrt {45}$
or, $c=3\sqrt 5$
or $c=6.71$ miles (approximately)
