How many edges does a tetrahedron have?

A tetrahedron is a three-dimensional shape that consists of four triangular faces. To determine the number of edges, we can analyze the geometry of the tetrahedron. Each triangular face contributes three edges, and since there are four faces, you might initially think to multiply the number of faces by the number of edges per face.

However, this counts each edge twice because each edge is shared between two faces. Therefore, to find the total number of distinct edges, you can multiply the number of faces by the edges per face and then divide by two:

[

\text{Total edges} = \frac{4 \text{ faces} \times 3 \text{ edges per face}}{2} = 6 \text{ edges}

]

Thus, a tetrahedron has 6 edges. This understanding of counting shared edges is critical in three-dimensional geometry and helps clarify the structure of polyhedra like the tetrahedron.