A lot of common objects are cubes. These include dishwashers, microwaves, ovens and a lot more!
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Many of these are rectangular prisms or cuboids, rather than cubes.
But sugar cubes, dice are some examples.
Dice. sugar cubes boxes Rubik's Cube ice cube building block
A ball, yea, thats totally in a cube shape.
desk
bread
balls
HUT
Many solid shapes could have 6 faces, but the most common such shape, with 6 equal faces, is the cube.
A star on a American flag
A dodecagon! its kind of obvious!
The most famous is a stop sign.
There are not many common nonagonal shapes. Some coins are nonagonal.
Rectangles are two dimensional objects- they have no thickness. Therefore you cannot "stack" them and so there will be no 3-D shape.