pyramid
pyramid
A cone
vertex vertex
pyramid
triangular prisum
triangle based pyramids
pyramid
The description given fits to that of a pyramid
Pyramid
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.
Octogon