Escape velocity is independent of the angle of projection because it relies on the conversion of kinetic energy to potential energy, which is not direction-dependent. This principle is rooted in the conservative nature of gravitational fields, where the work done does not vary with the path taken. In an ideal scenario without atmospheric resistance, any launch angle will ultimately lead to a trajectory that approaches a straight line away from the planet. Geometrically, since escape velocity aims to reach infinity, all paths converge to a direction that is effectively away from the gravitational source. Thus, the angle of projection does not influence the required escape velocity.