1. 
   Antiprism
   In geometry, an n-sided antiprism is a polyhedron composed of two parallel copies of some particular n-sided polygon, connected by an alternating band of triangles. Antiprisms are a subclass of the prismatoids. Antiprisms are similar to prisms except the bases are twisted relative to each other, an...
   Found op http://en.wikipedia.org/wiki/Antiprism
   
   
2. 
   antiprism
   A pentagonal antiprism A semi-regular polyhedron constructed from two n-sided polygons and 2n triangles. An antiprism is like a prism in that it contains two copies of any chosen regular polygon, but is unlike a prism in that one of the copies is given a slight twist relative to the other. The...
   Found op http://www.daviddarling.info/encyclopedia/A/antiprism.html
   
   

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