This video is another in the series of videos looking at the topic area of Geometric Reasoning. It's important in maths to know the difference between 2D and 3D shapes (otherwise known as solids). We take a look at particular types of solids called Polyhedron/Polyhedra and can relate faces, edges, and vertices together to form Euler's Rule. Examples are given of lots of solds and how they are used in Mathematics.