I'm still somewhat new to 3D CAD software (<~1 year experience with AutoCAD) and am completely new to SolidWorks. I have created a cover in the shape of half of an ellipse. It is 1500mm long, 400mm wide and 400mm tall. (i.e. it's a horseshoe shape). I now want to add a "trap door" to it. How do I add the door to follow the contour of the cover and tell SolidWorks that it's a moving door with hinges?