The slope diagram is limited to theoretical loading. Friction plays a much bigger part in a slope raise/lower than it does in the situations represented by the other two diagrams. The friction of the load on the slope cannot be determined by the angles involved. Furthermore, if the load in question includes people who are walking on the slope this complicates calculations further. The people could lean back pull against the rope or actively walk up the slope thus decreasing the load on the rope.
Drag the top and bottom of the slope to match the situation you want to calculate. The blue horizon line will always be horizontal and the load line always points straight down (gravity).