The travel of the boat has a shape of a right angle triangle
To find the total distance, first, we will find the length of the hypotenuse
So, as shown and using the Pythagorean theorem the hypotenuse will be =
[tex]\sqrt[]{4^2+5^2}=\sqrt[]{16+25}=\sqrt[]{41}=6.4[/tex]So, the total distance = the perimeter of the triangle =
[tex]4+5+6.4=15.4[/tex]Rounding to the nearest mile
So, the answer will be option C) 15 miles