Geometrical 3D forms

maybe for your math-lesson

cone, cube, cuboid, cylinder, sphere, prism3, prism6, pyramid4, pyramid3, pyramid frustum, cone frustum, torus

with OPENSCAD-Files (parametric, easy to change)
for OPENSCAD-beginners: Change Parameter, press F5 for preview, then F6 for rendering, then export to stl

very easy to print, infill 0.1