Question: How do we identify solids?

Answer: A solid, which is also known as a 3D object because it has three dimensions: width, depth, and height.
Solids have two properties that make them solids: they have surface area and volume.
Volume is the space inside an object, and surface area is the outer measurement of the object.

Okay, so now let me tell you that there are two different types of solids: Polyhedra and Non-Polyhedra.

The rule for Polyhedra solids is that all the sides must be flat surfaces.
Examples of these types of solids are shown below:

The rule for Non-Polyhedra is the opposite, if one or more of the sides is curved then it is a non-polyhedra.
Examples of these types of solids are shown below:

NOW YOU TRY! :D

What type of solid is the shape below?