Express the Force in Cartesian vector form (converting a Position vector into a Force vector)

In this Statics problem, we go through the process of forming a Force vector by starting with a position vector that's in the same direction as the force

Problem Statement:
The window is held open by chain AB. Determine
the length of the chain, and express the 50-lb force acting at
A along the chain as a Cartesian vector and determine its
coordinate direction angles.