A solid figure with twenty faces is called an Icosahedron.
A cube is a solid figure called a polyhedron. A polyhedron is a solid figure with all flat faces. So a cone would be a solid figure but not a polyhedron becasue it has a curve and does not have all flat faces.
A polyhedron with 20 faces is called an icosahedron.
The regular solid, with 20 identical equilateral triangular faces, is called an icosahedron.
'Enneahedron' - a solid figure with nine faces
were two or more faces of a solid figure
A decaredra is the ten face solid figure.