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.
4
a square based pyramid.
The tetrahedron has 4 equilateral triangles as its faces.
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A tetrahedron
Tetrahedron or triangular pyramid.
sphere
The geometric shape that has 1 square face and 4 triangular faces is a pyramid. A pyramid also has five vertices and eight edges. The square acts as the base for the shape on which it sits.
There is no 3-d shape with 4 and 1 = 5 triangular faces.
A square based pyramid.
Square pyramid.
There is no such shape as a regtangiel. If you meant a rectangle, that is a 2-dimensional shape with 4 vertices, 4 edges and one face.