A deltahedron is a polyhedron which is composed of equilateral triangles as faces.

pentagonal antiprism, pentagonal deltohedron(not deltahedron), decagonal pyramid, and many more.

In geometry, a deltahedron (plural deltahedra) is a polyhedron whose faces are all equilateral triangles. The name is taken from the Greek upper case delta (Δ), which has the shape of an equilateral triangle.

look at ask or google to find an answer

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A polyhedron with equilateral triangular faces is called a deltahedron. There are infinitely many of them but only 8 convex ones. The following three are regular:

tetrahedron, octahedron and icosahedron.

There are 5 more convex polyhedra which are convex but not regular (because they have differing number of faces meeting at their vertices) These are Johnson deltahedra (see link).

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