This is a beautiful example of a single sheet Origami model by Tomoko Fuse. The top is pyramid shaped and made of only one piece of A4 paper. The bottom is also only made of one single sheet of A4 paper. There are many other Origami triangle box models that I know, but only very few that are single sheet models. The big advantage of single sheet Origami is the stability. The downside would is that you cannot form colorful patterns like you can when building modular Origami boxes.
You will need 2 A4 sheets of paper.