Yes, its called a three sided pyramid
A pyramid
A triangular based pyramid has 4 flat faces, 6 edges and 4 vertices.
It is a pentahedron with a rectangular base and four triangular lateral faces.
Two shapes with five faces are a triangular prism and a square pyramid. A triangular prism consists of two triangular bases and three rectangular lateral faces, while a square pyramid has a square base and four triangular faces that converge at a single point (the apex). Both shapes exemplify polyhedra with five distinct surfaces.
A pyramid has a total of ( n + 1 ) plane surfaces, where ( n ) is the number of triangular faces. For example, a square pyramid has a square base (1 surface) and four triangular faces, resulting in a total of 5 plane surfaces. The specific number can vary depending on the shape of the base; for instance, a triangular pyramid (tetrahedron) has 4 surfaces in total.
Flat surfaces on a pyramid are known as faces. A pyramid typically has a polygonal base and triangular faces that converge at a single point called the apex. The number of triangular faces corresponds to the number of sides of the base polygon. For example, a square pyramid has one square base and four triangular faces.
A square-based pyramid has five flat surfaces: one square base and four triangular faces that converge at the apex. The base is the square, while each of the four sides of the square forms a triangular face with the apex.
A triangular pyramid.
NO such object as a 'triangular pyramid'. This object is named a 'TETRAHEDRON'. The word 'tetrahedron' ,from classical languages, means 'tetra/four(4)' and 'hedron/solid object'. A tetrahedron has four(4) triangular faces. A pyramid has four(4) triangular faces, and a square base, making for five(5) faces. It is erroneously named ' a square pyramid', but there is no0 such thing.
A square base, and four triangular shaped sides equals five flat surfaces.
Trapezium, or triangular pyramid * * * * * A triangular pyramid, yes. But not a trapezium since that does not have four triangular faces.
A triangular pyramid has four triangular faces.