In triangle PQR, we have angle P=90°, QR= 20, and Tan R = 4sinR. What is PR?
tan R = sin R/cos R
sin R/cos R = 4 sin R
cos R = 1/4
PQ = 5
so by Pythagoras
PR = 5*sqrt(15)
Sorry that's incorrect :(
angle R = 75.52248781º
PR = 20 * cos(R) = 5
PQ = 19.36491673
+47 
