Not to trying to be sarcastic, but it's called 3 dimensional artwork. The phrase '3D artwork' is to vague to place a specific label on it since it can cover sculptures, pottery, paintings that have a 3D perspective, digital 3D art, and so on.
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three-dimensional artwork
A pyramid
No. A polygon is a 2-dimensional figure. A polyhedron is 3-dimensional.
3-dimensional, if it's in real life. If it's merely a picture, then it's a 2-dimensional object depicting something that's 3-dimensional.
A painting is a two dimensional artwork; a sculpture is a three dimensional artwork.
The differences between 2-dimensional and 3-dimensional artwork are the differences between a painting and a sculpture. A painting, a drawing, a photograph, are all 2-dimensional, existing on a flat canvas or piece of paper, or on a wall, etc. A sculpture, a mobile, etc., are 3-dimensional objects that may be hung from or stand on a surface, but have length, width and height.
A 3-dimensional parallelogram is a parallelepiped .
A 3 dimensional figure
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form
Two dimensional artwork is the kind of art you typically see in a frame. I.e. it is flat or on one plane. Examples include watercolors, photographs, lithographs, oil paintings, etc. This artwork has a length and a width, but no depth or height.Three dimensional artwork has depth or height in addition to length and width. Examples include sculpture, carvings, ba relief etc.Some people make three dimensional art in a frame (e.g. some collages and some masks). These are still considered three dimensional.
three-dimensional artwork
three-dimensional artwork
Paintings before the Renaissance: people saw in only a 2 dimensional figure, but in the Renaissance, people saw art in a 3 dimensional figure. Painters in the Renaissance gave attention to body size, proportions, perspective, and detail.
Drawing and painting are two-dimensional, sculpture is three-dimensional.
It depends on what media the artwork is. For two dimensional and digital pieces (and maybe three dimensional, I'm not 100% sure), there is a website called deviantART where you can sell your artwork as posters. You can also auction your artwork on eBay if you request a reasonable price.