The TETRAHEDRON question

We played a game online called “Fling the teacher”.  We got the last answer wrong because it was TETRAHEDRON and we didn’t know what that was.  Edward went home and did some research.  He found out that a tetrahedron is a 3D shape that has four faces.  That means a triangular pyramid is a tetrahedron.  Edward looked on the internet, in a maths dictionary and even made one from a net.  Thanks Edward that was really great thinking.