Improper Integral 1

Calculus Level 3

Given that $\displaystyle \int _{ a }^{ \infty }{ \frac { { e }^{ x } }{ { 9e }^{ 2x }+64 } dx=\frac { \pi }{ K } }$ , where $a=\ln { \left(\frac { 8\sqrt { 3 } }{ 3 } \right) }$ , what is the value of $K$ ?