Square Pyramid
There is a contradiction in your question. If the base has four equal sides then is it a square so not all the faces are Triangles. However if the base is a square and the rest of the faces are triangles then your object is a "Square-based Pyramid"
The figure is a pyramid and the base is a square.
A pyramid
A square based pyramid.
a square pyramid (i found it in my sons math book !)
pyramid. Base is a square, but each of the 4 sides is a triangle.
A solid figure with five faces is called a pyramid. Specifically, a triangular pyramid, or tetrahedron, has four triangular faces, while a square pyramid has one square base and four triangular faces, totaling five. The pyramid's faces meet at a single point called the apex.
A pyramid with a square base.
A three-dimensional figure with a polygon base and triangular faces that meet at a common vertex is called a pyramid. The base can be any polygon, such as a triangle, square, or pentagon, and the apex is the common vertex where all the triangular faces converge. Pyramids are named based on the shape of their base, such as triangular pyramids or square pyramids.
A square pyramid has a square base and four congruent triangular faces.
The 3D shapes that have all their faces equal to their base are known as regular polyhedra. Specifically, these include the tetrahedron (4 triangular faces), cube (6 square faces), octahedron (8 triangular faces), dodecahedron (12 pentagonal faces), and icosahedron (20 triangular faces). Each of these shapes features congruent faces that exhibit symmetry.
A right, square based pyramid.A right, square based pyramid.A right, square based pyramid.A right, square based pyramid.