What is the period style of Alvin Loving's "Steptehedron"?

I'm writing an essay for my art history class and I honestly don't even know what period style refers to and I can't seem to find anything online thats dumbed down enough for me to understand.
It's a geometric, abstract piece painted in 1970.

2019-07-09T00:19:43Z

Also can anyone tell me what the title means? Google is pretty convinced it's just not a word.

Anonymous2019-07-09T00:21:37Z

period style is Baroque, Romantic, Impressionist, Abstract, Surrealism, Cubism, Dada, etc.