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Tetrahedron
A tetrahedron is a solid figure with 6 edges. There's no such thing as solid edges. A tetrahedron is a triangular pyramid, with 4 vertices, 6 edges and 4 triangular faces. In a regular tetrahedron (the first Platonic solid) all triangles are equilateral.
The tetrahedron, consisting of four regular triangles.
A solid figure with nine edges is known as a triangular prism. It consists of two triangular bases connected by three rectangular faces, resulting in a total of nine edges: three edges from each triangular base and three edges connecting the corresponding vertices of the triangles.
Triangular prism
triangular prism
square-based pyramid
The Platonic solid with twenty faces that are equilateral triangles is the icosahedron. It is one of the five Platonic solids and is characterized by having 12 vertices and 30 edges. The icosahedron is known for its symmetrical properties and is often associated with the element of water in various philosophical traditions.
solid with 2 edges is a cylinder
A solid shape made out of eight equilateral triangles is called a triangular bipyramid. This polyhedron consists of two triangular pyramids (tetrahedra) joined at their bases, creating a three-dimensional figure with eight triangular faces, six edges, and four vertices. The symmetry and uniformity of the equilateral triangles give it a distinct geometric shape.
A triangular based pyramid seems to fit the description which has 4 faces, 6 edges and 4 vertices
The Johnson Solid J89, named Hebesphenomegacorona, has21 faces, of which 18 are triangles and 3 are squares.It also has 33 edges and 14 vertices.