Solve the Problem $\left( 9 \mathrm { mi } , 20 ^ { \circ } \right)$

Multiple Choice

Solve the problem.
-The locations, given in polar coordinates, of two planes approaching an airport are $\left( 9 \mathrm { mi } , 20 ^ { \circ } \right)$ and $\left( 2 \mathrm { mi } , 71 ^ { \circ } \right)$ . Find the distance between the two planes.

A) $\approx 7.9 \mathrm { mi }$
B) $\approx 51.48 \mathrm { mi }$
C) $\approx 9.22 \mathrm { mi }$
D) $\approx 8.42 \mathrm { mi }$