Can ypu please help with my sons homework question which is - Name two 3-D shapes that have 7 faces
I think it is called a heptahedron, but check to be sure.
* * * * *
A heptahedron is a generic name for any solid with seven polygonal faces. If its is you son's homework, it is likely they are looking for more specific examples. Here are two: A pentagonal prism and a hexagonal pyramid.
A 3-D shape that has 8 faces is a hexagonal prism. This is a shape that is formed on a hexagon-shaped base.
triangular based pyramid
An octahedron is a closed 3-d shape with 8 polygonal faces. There are 257 topologically different convex octahedra. They can have faces which are triangles, quadrilaterals, pentagons, hexagons or heptagons.
Octagon. * * * * * An octagon is 2-dimensional. The regular 3-d shape (all faces the same) is the octahedron, but a hexagonal prism also has 8 faces.
8 * * * * * There is no 3-D shape made from regular hexagons. The previous answer may refer to a hexagonal prism. But that is not a 3-D hexagon: the shape has two hexagonal faces and six rectangles - not just hexagons.
A 3-D shape with 8 faces is an octahedron.
An octahedron is a closed 3-d shape with 8 polygonal faces. There are 257 topologically different convex octahedra. The number of faces at a vertex ranges from 3 to 7.
-4
tetrahedron
Pyramid
octahedron
All of them.
The Euler characteristic for polyhedra then requires that thye shape has no vertices! And that means it cannot be a polyhedron. I suggest you count the faces and edges again.
-9
A cone
There is no such 3-d shape if it also has flat faces.
-3