pyramid
The answer is a polyhedron
Tetrahedron
if you mean common: one of the triangle, square, and pentagon vertion of pyramid, dipyramid, and gyrolongated dipyramid. a total of 9.
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hexagon, square
A regular polyhedron has equal size faces as in the case of a tetrahedron which is a triangular base pyramid that has 4 equilateral triangle faces.
What polyhedron has eight sides and all of the are equilateral triangle?
7 faces
No, tetrahedron is a polyhedron with four faces.
It is a triangular based pyramid
A regular OCTAHEDRON.
that's easy its a triangle * * * * * That is such a nonsensical answer! A triangle is not even a polyhedron. The correct answer is an octahedron - two square based pyramids stuck together along their bases.