Look at the polyhedron that you chose at the beginning. Which two solids do you need to create your polyhedron? How many of each solid do you need?

2 Tetrahedrons combined create an Octahedron.

Step-by-step explanation:

Despite the lack of information.

The Plato Polyhedrons are Tetahedron, Cube (Hexaedron), Dodecahedron, Octahedron and Icosahedron. They are regular ones, made up by regular plane figures.

An Octahedron can be built by combining two pyramids. Each Tetrahedron is made up by 4 equilateral triangle.