(Solved): A 135-lb cylinder is supported by two cables AC and BC that are attached to the top of vertical p ...

A 135-lb cylinder is supported by two cables $AC$ and $BC$ that are attached to the top of vertical posts. A horizontal force $P$, which is perpendicular to the plane containing the posts, holds the cylinder in the position shown. Knowing that: $\begin{array}{l}a=10.5\mathrm{ft}\\ b=16.4\mathrm{ft}\\ c=3.0\mathrm{ft}\\ d=6.9\mathrm{ft}\end{array}$ Calculate the value of the force $\mathrm{P}$ and enter your answer to one decimal point. Include units.