Eight.
Infinitely many planes of symmetry
9 planes in Cube 3 Planes in Cuboid
4
That depends on what you mean as a diamond. If you're referring to the simple two dimensional shape that's really just a rotated rhombus, then it has two (four if it happens to be square). If you're referring to the actual crystal then - in it's perfect form - it would be an octahedron, which has five planes of symmetry.
Eight.
14
Infinite
There are 3 planes of symmetry in a rectange.
there is 9 planes of symmetry in a cube
it has 5 planes of symmetry
Infinitely many planes of symmetry
There are infinite planes of symmetry in a cylinder in the same way that a circle has infinite lines of symmetry.
A rectangular solid that is not a cube has 3 planes of symmetry.
This depends on the type of prism. If the shapes on the ends are pentagons, the prism has 6 planes of symmetry. If they are hexagons, it has 13 planes of symmetry. It has the same number of planes of symmetry as the shapes on the end have lines of symmetry, plus 1.
There are no lines of symmetry in a 3d figure.The right question is how planes of symmetry are there in a pentagonal pyramid.Then the correct answer is 5 planes of symmetry.
9 planes in Cube 3 Planes in Cuboid