Thank you very much, by the way i would like to add a wall on both sides of the ramp how will i do it?
You could use JointPushPull - by vector i think - again to project the ramp face vertically so that it is all below the ground plane. Draw a large rectangle on the ground plane.
Select the rectangular face and Edit/Intersect faces/With model and clean up to leave a projected outline of the ramp on the ground.
Offset its side faces to your desired wall thickness. Close the ends. Use ordinary pushpull to create the walls, taller than you need.
Then trim the tops parallel to the ramp top face using a similar method - a sloping plane to define the top face, roughly parallel to the top face (which isn’t a plane, of course).
Or more accurately, JointPushPull the top face of the ramp to the height you want, scale it along the red axis (in Mihai’s view above) to intersect the walls, and trim off the top.
Thank you very much!