There are very many possible shapes:
a square based pyramid
a triangular prism
a square anti-prism
a cuboctahedron
a rhombicuboctahedron
and possibly more.
See link for images.
Pyramid
square
Cube
Cylinder
Pascal's triangle was invented by Blaise Pascal (1623-1662) in 1653. Although it has been named after blaise pascal, there have been traces of the triangle, long before Blaise Pascal was born. It is belived that the Persians and the Chinese had been using it to find the square and cube root of numbers. Whoever asked this question is a complete idiot, because the answer is in the question.
Where were the traces of the past found
You didn't say if you wanted it used as a noun or a verb so here are two sentences.There were no traces of the criminal.When he traces the picture, he always adds something to it.
Where were the traces of the past found
Traces of Smoke was created in 1992.
Traces of a Dragon was created in 2003.
Traces of Death was created in 1993.
A Matter of Traces was created in 1958.