Modeling Ramps In SketchUp Without Plugins | make Slope Path 

Depends on shape creation

@@CivilSurvey shape can be formed but the ramp end won't be in straight horizontal surface. For that, plugin tool like curvishear has to be used.

It's just tutorial you can make better shape

@@CivilSurvey If I make a ramp that way I won't have any control over its slope, which won't be constant either.

You can use pancel or measure tape give a size vertical or horizontal ratio slope and make diagonal line then push it..boy many ways

I find it very helpful for landscape design to create topiary hedge 👍