What is a Net? | Geometry Review
This video shows several examples of nets, both in prism and pyramid forms. When working with nets, you want to imagine folding them up to form a 3D figure.
Which of the following nets can and cannot be used to form a prism? When working with nets, you want to imagine folding them up to form a 3-D figure. Let’s look at our first net.
If I were to fold this, I would fold this side around and fold these two sides around where this edge would meet this edge. These two bases would overlap each other and the top would be open. This one would not form a prism.
Our next one, if we folded this up, the side lengths of the end faces do not match the lengths of the faces that would be joined to them. The dimensions aren’t right for this net to work either.
On this last one, we simply don’t have enough faces. Presumably, these would be our bases. Since they have four sides, then we would need four rectangles for lateral faces to connect them together. That means that none of these nets would form a prism.
Which of the following nets can and cannot be used to form a pyramid? Our first one- again, we imagine folding it up. If we folded these flaps in, they would- they’re so small that when they meet they would simply just form another square, just like our base. We have another flat square on top of our flat square.
Not a pyramid, because we would just have two squares on top of each other. In our next net, we have two squares. In a net, you can only have one face that isn’t a triangle. This one also would not form a pyramid.
Our last one though, if we folded these triangles up on our lines, then we would end up with a triangular pyramid with a triangle as a base. This one would form a pyramid. The other two would not.