In triangle $PQR$, we have $\angle P = 90^\circ$, $QR = 15$, and $\tan R = 5\cos Q$. What is $PQ$?
PQ = 8*sqrt(3).
tan(R) = 5 * sin(R)
Angle R ≈ 78.46304º
PQ = sin(R) * QR
+501 
