One.
one, the cone
a cuboid
a cone
the difference between a cone and a prism is that a cone has no edges and only one vertex and a prism has both edges and vertexes.
A cone has infinitely many planes of symmetry because its base is a circle, which also has an infinite amount of planes of symmetry. Prove it by making a 3D model of it and they look at the number of vertexes.
8 vertexes
Not sure about vertexes or prisim. A rectangular prism, on the other hand, has 8 vertices. Not vertexes.
A cylinder has no vertices (not vertexes!) It has 2 circular edges.
6 edges 4 vertexes
there are 2 Faces on a cone, there is a technically immeasurable amount of corners, because the ca just keep cutting the angle finer and finer on the circular end and making more corners. though you'll get your bottom whipped if you say this to your teacher, the amount of vertexes on a cone is: 1+(∞)
4