The diagram shows a cuboid. Part a) How many vertices does a cuboid have? And part b) How many faces does a cuboid have?
So first of all, we look at part a, and we want to see how many vertices the cuboid has. Well, what is a vertex? Well, the definition of a vertex is a point where two or more curves, lines, or edges actually meet. So what it means, when we’re looking at something like this, so we’ve got a 3D shape like our cuboid, is it’s actually the point where the corners are, so that’s our vertices.
So what I’ve now done is actually circled all the vertices on our cuboid. And if we actually count these up, we can see that actually our cuboid has eight vertices. So part a) solved, a cuboid has eight vertices.
Okay, so now let’s look at how many faces the cuboid has. So like I said, in part b), we’re looking for faces of the cuboid. Well, if we think about what are faces, well a face is actually a flat surface of a one of our 3D shapes, so one of our flat surfaces is a face. So how many faces has it got?
Well, let’s count them. So first of all, we have one at the top and one at the bottom, so that’s two, then a face at each end, so that’s three four, and then a face at the front and a face at the back, which is five six. So we say it’s got six faces.
So there we go, we’ve actually answered the question. So we’ve got part a) and part b), our cuboid has eight vertices and six faces, respectively.