You would need to use Carbide Create Pro or a full-fledged 3D CAD and CAM setup.
Modeling a taper in Carbide Create Pro requires a stock area twice the size of the ramp which you wish to angle —
EDIT: Or, a gradient pixel image which can be imported as a depth map END EDIT
See below for a separate post detailing this.
A quick/easy work-around would be to make a taper fixture which would hold the stock at the required angle and accept some air cutting.
Doing this in Carbide Create itself would require drawing things up in profile and drawing a bunch of geometry with ball-nosed tools and would require a great deal of patience to make a file which wouldn’t require a lot of sanding, see: