Question 834934
This is a triangle, the departure point is at an angle 10 degrees.  One side of this angle is 7.2 km, and the other side of this angle is 8 km.  The last side of this triangle is how far you are from the other end point of the 8 km. side.


Draw this triangle to see more comfortably.


Law of Cosines.
How far you are, that unknown side, d.

{{{7.2^2+8^2-2(7.2)(8)cos(10)=d^2}}}
{{{highlight(d=sqrt(7.2^2+8^2-2(7.2)(8)cos(10)))}}}