FTCE Professional Education Practice Exam

What is the geometric term for a solid shape with all triangular faces?

1. A tetrahedron

2. A cylinder

3. A cone

4. A pyramid

The correct answer is: A tetrahedron

A solid shape with all triangular faces is referred to as a tetrahedron. This geometric figure specifically has four triangular faces, six edges, and four vertices. Each face of a tetrahedron is an equilateral triangle, contributing to its overall triangular structure. In broader terms, while pyramids also have triangular faces, they can have a base that is not triangular, such as a square or rectangular base. A pyramid has at least one base that is a polygon, with triangular faces converging at a point called the apex. Conversely, a tetrahedron is unique in that it possesses only triangular faces throughout, making it a specific type of pyramid with a triangular base. Other options like the cylinder and the cone do not fit the criteria at all, as they include curved surfaces rather than only triangular faces. This understanding highlights the defining characteristics of a tetrahedron and distinguishes it from other solid shapes.