what are representational shapes?

Look up Brancusi- here's his entry on Artcyclopedia, with links to a lot of museums and galleries with images:

http://www.artcyclopedia.com/artists/brancusi_cons...

A lot of his work is called "representational" because he simplifies and abstracts forms; that is, his sculptures don't attempt to replicate what our eyes see, but he uses shape, contour and texture to represent reality.

A great example is Bird In Space (1923) http://www.metmuseum.org/works_of_art/collection_d...

although, when you think about it, all art, every shape created by man is representational. Even the most realistic human scuplture is merely a representation of reality. Drawing a circle is only a representation of the abstract concept of "circle." So, the answer to your question is, everything

Representational Shapes

A shape that looks like something real - it represents a shape you would identify - like the silhouette of a head or the shape of a boat or any other object. The alternative is an abstract shape that is just an interesting shape, like an oval or a square or a blob.