Edges meet at a vertex.
must all edges of semiregular polyhedron be the same length
It is not a regular polyhedron because it has unequal sides
A polyhedron must have at least 4 faces, at least 4 vertices and at least 6 edges.
Heptahedron
A polyhedron has 30 edges and 12 vertices. How many faces does it have
A 20-sided polyhedron is called an icosahedron. It has 20 equilateral triangle faces, 30 edges, and 12 vertices. It is a regular convex polyhedron with rotational symmetry.
Not necessarily. If all faces are equilateral triangles (all edges are equal length) then it is a regular polyhedron.
A cube.
That depends on the kind of polyhedron.There are five kinds of regular polyhedra (all edges of equal length).Tetrahedron (four-sided pyramid) has 6 edgesHexahedron (cube) has 12 edgesOctahedron (eight-sided solid) has 12 edgesDodecahedron (12-sided solid) has 30 edgesIcosahedron (20-sided solid) has 30 edgesIt is also possible to have a polyhedron that is not regular, with almost any number of sides and edges.
I do not believe that such a shape exists.
Yes. A polyhedron is a geometric shape with flat surfaces and straight edges, so a a pyramid with a rectangular base qualifies as a polyhedron. It is however not a regular polyhedron, which would require all the faces to be the same shape and size. To change your pyramid to a regular polyhedron you'd have to turn it into a tetrahedron.
An icosahedron is a regular polyhedron with 20 identical equilateral triangular faces, 30 edges and 12 vertices. It is one of the five platonic solids.
False
False
No. The numbers do not satisfy the Euler characteristic.
The number of edges and vertices ina polyhedron will depend on the polyhedron one selects either to study, build or etc...