A prism. A prism is named for its base, eg a triangular prism has a triangle for the base. If the base is a circle, the circular prism is called a cylinder.
Square
Square
80 units cubed (I assume 'base' means base of the triangle)
The base of a pentagonal prism is a pentagon. Just like a square pyramid has a square for a base, a pentagonal prism has a pentagon for a base.
A prism. A prism is named for its base, eg a triangular prism has a triangle for the base. If the base is a circle, the circular prism is called a cylinder.
Square
Square
A cone has a circle for a base and a triangular prism has a triangle for a base
A hexagonal prism's base is called a hexagonal base. The names of prisms are given according to the shape of their bases. A hexagonal prism has a base that is shaped like a hexagon. Similarly, a pentagonal prism has a pentagonal base.
It is a cone
A hexahedron is a 3D shape with 6 faces. It CAN be a prism whose base is a square. But that is only one example. It can also be a prism whose base is any quadrilateral. It can also be something like a pentagonal pyramid (i.e. the base is a pentagon and the sides are made up of 5 triangles.)
A Base!
An octagonal prism.
Cylinder
192
A cylinder has a circle as a base, while a prism has either a triangle (most common) or a rectangle as a base.