How would I make a plane with a hollow cylinder and a flat bottom, like a skateboard half pipe?

Question

How would I make a plane with a hollow cylinder and a flat bottom, like a skateboard half pipe?

I am just thinking about making a primitive shape. No details are other than a shape. A side view would be akin to this " --U--" but flush with the top and a bit of flat bottom.

This is my first blender project, so I hope this question is appropriate.

Answer 1

add a mesh circle, select the upper part and delete it

now select the right part

and move it to the right

now select these two vertices

and subdivide

select the vertex in the middle and use snap -> vertex

now press G Y and move the cursor on this vertex so that the selected vertex has the same height

then move that vertex to the right like this:

now select these two vertices

and press E S X and move your mouse so you got this:

now press A E Z and move your mouse you will get:

now TAB and right click -> autosmooth