Tetrahedron.
square
triangular prism
square-based pyramid
sphere
Tetrahedron
A tetrahedron
Equilateral triangle ,acute triangle
Isosceles TetrahedronA solid with four faces is a tetrahedron. Each of the faces is a triangle. If all the triangles are congruent, you have an isosceles tetrahedron.
Octohedron
cylinder
oblique prism
octohedron