When I type “Trun” in the command line Truncated Pyramid appears but Truncated Cone does not.
it’s TCone
(not TruncatedCone)
fwiw, when learning rhino, it’s helpful to make it habit to always check command history when using icons/menus… to me, that was, i think, the most helpful way for me to learn the command names…
for instance, use the icon for truncated cone in the solids then look at the bottom-left of the screen… you’ll see _TCone listed there