pentagon triangle(20) triangle(4), meaning 'dit'. The other words represented are, respectively: sit, tic, and dis. The 2-dimensional shapes given were:

circle, square, triangle(4), pentagon, and triangle(20). Their respective 3-dimensional counterparts are: sphere (3-dimensional circle), cube (made up of 6 squares), tetrahedron (made up of 4 triangles), dodecahedron (made up of 12 pentagons), and icosahedron (made up of 20 triangles).

The first letter of each 3-dimensional counterpart was used to form the various 3-letter words. Yes, this was tough!!

Winner: Ed Smock, Monmouth,IL