A hexagon. (A six-sided shape)
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A regular octahedron.
A three-dimensional shape with eight triangular faces is called an octahedron.
A cube.
a hexahedron with four rectangular sides and two square ends.
Octahedron. (i assume your talking about something three dimensional).
Sides and faces are the same thing, and an octahedron has eight.
A square pyramid has a base with 4 equal sides and triangular faces.
What polyhedron has eight sides and all of the are equilateral triangle?
An octagon
If, by "sides" you mean faces, then the answer is a pentahedron.
A regular 8 sided octagon has eight equal sides.
triangular pyramid-4 equal faces
square pyramid