Abstract: Construction elements have two oppositely arranged, connected body portions each having an external surface configuration disposed in the planes of a particular preselected triangular shape. Each body portion has three, outwardly converging, tapered projections with each having one of its projections cut off at a narrower end portion and the cut-off projections are connected together to provide four outwardly extending projections which serve as male connectors. Two adjacent projections extend in the same direction along spaced parallel planes and two projections are oppositely arranged to project out in generally opposite directions. An inwardly converging recess is formed between the adjacent projections which serves as a female connector to interfit with complementary male connectors.