A polygon.
L shape
all of the shapes
triangle * * * * * A triangle is NOT a 3d shape! A cube.
A triangle for example has 3 vertices.
A cuboid.
Rhomboid
Well, darling, any shape that isn't a boring old circle has more than one vertex. So we're talking about your sassy squares, your feisty triangles, your rebellious rectangles, and even those wild pentagons and hexagons. Basically, if it's not round, it's got more than one vertex.
Almost any 2D/3D shape has more than one vertex. Triangles, squares, rectangles etc. etc.
A diagonal in a shape is a straight line from one vertex to another vertex (corner).
A cone has one vertex and one edge.
tetrahedron