In triangle PQR, let X be the intersection of the angle bisector of angle P with side QR, and let Y be the foot of the perpendicular from X to line PR. If PQ = 9, QR = 9, and PR = 9, then compute the length of XY.
The angle bisector from P bisects QR in X.
\(sin\ 60 ^{\circ}=\dfrac{\overline{XY}}{0.5\cdot \overline{QR}}\\ \overline{XY}=0.5\cdot \overline{QR}\cdot sin\ 60^{\circ}=0.5\cdot 9\cdot sin\ 60^{\circ}\\ \color{blue}\overline{XY}=3.897\)
!