Solve the Problem $\left( \mathrm { x } \mathrm { mi } , 70 ^ { \circ } \right)$

Solve the problem.
-The locations, given in polar coordinates, of two planes approaching an airport are $\left( \mathrm { x } \mathrm { mi } , 70 ^ { \circ } \right)$ and $\left( 3 \mathrm { x } \mathrm { mi } , 130 ^ { \circ } \right)$ . Find an expression in terms of $x$ for the distance between the two planes.

A) $x \sqrt { 7 } \mathrm { mi }$
B) $x \sqrt { 10 - 3 \sqrt { 3 } } \mathrm { mi }$
C) $x \sqrt { 10 } \mathrm { mi }$
D) $x \sqrt { 10 - 3 \sqrt { 2 } } \mathrm { mi }$