a triangular based pyramid
a tetrahedron
A triangle-based pyramid.
A triangular based pyramid with 4 equilateral triangle faces is a tetrahedron
name which containig triangle prism and triangle pyramid
a triangular based pyramid
a tetrahedron
A triangle-based pyramid.
A tetrahedron, though a triangular pyramid is a perfectly acceptable name.
A triangular based pyramid with 4 equilateral triangle faces is a tetrahedron
name which containig triangle prism and triangle pyramid
Pyramid
equalateral triangle
A six sided polyhedron is a hexahedron. This may be a triangle based dipyramid, a pentagonal pyramid of a variant of a parallelepiped.
A square based pyramid is a 3-d object. It does not have a 2-d name!
three demensioned isolated triangle.
A square based pyramid is the best name. It is a pentahedron, but that could also refer to a pyramid on any quadrilateral base and so the name is far less informative.