a pyramid
pyramid
A cone
pyramid
vertex vertex
pyramid
triangular prisum
pyramid
triangle based pyramids
Pyramid
The description given fits to that of a pyramid
Octogon
The solid figure that has 4 flat surfaces that are triangles is a tetrahedron. A tetrahedron is a polyhedron with four triangular faces, six straight edges, and four vertex corners. Each of the four faces of a tetrahedron is an equilateral triangle, making it a regular polyhedron.