This shape is called a Icosahedron , I think.
Icosahedron
An equilateral triangular pyramid
An Icosahedron.
octahedron
An icosahedron.
An octahedron.
Octahedron- A polyhedron with eight faces. All faces of a regular octahedron are congruent, equilateral triangles.
The minimum numbers of congruent faces are as follows: On an equilateral triangular prism: one pair of triangles On a right equilateral triangular prism: one pair of triangles and one triplet of rectangles.
It is a regular triangle pyramids
An icosahedron is a shape with twenty equilateral triangles as faces.
A tetrahedron, or triangular pyramid, has four congruent equilateral triangles as its faces. Each face is an equilateral triangle, and the tetrahedron is a three-dimensional shape with four vertices and six edges. This symmetry gives the tetrahedron its unique geometric properties.
A solid with 8 faces is an octahedron.As all faces are the same it is a regular octahedron.As such it is one of the five platonic solids - the only five 3D objects that can be regular: the tetrahedron (4 equilateral triangles for the faces), the hexahedron (usually called a cube with 6 square faces), the octahedron (as asked, 8 equilateral triangles for the faces), dodecahedron (12 regular pentagons as faces), icosahedron (20 equilateral triangles as faces).