The tetrahedron. If one of the four triangles is equilateral and all others are isosceles, then one might also call it a (triangular-based) pyramid.
its a triangle, circle,
Pyramid
There is no such shape.There is no such shape.There is no such shape.There is no such shape.
A triangle based pyramid.
triangle based pyramid
a square pyramid
There is no such thing as a 3d triangle. A 3d shape which has only equilateral triangular faces can be a tetrahedron which has 4 faces or an icosahedron which has 20.
Pyramid
Triangle
a square. duuh. * * * * * duuh is correct! A square has 4 identical sides or 4 identical angles but not 4 identical faces! A shape with four identical plane faces is a regular tetrahedron or a triangle based pyramid.
tetrahedron
The shape you are after is the tetrahedron or triangle based pyramid, which is one of the five platonic solids.