a toy building element has sidewalls that include grooves and tongues by which the toy building element can be interconnected with a like building element . each groove is formed between a pair of outwardly extending flexible ridges . the tongue does not extend outward beyond the virtual plane of the sidewall that includes the tongue . the virtual plane is defined as a plane that passes through a midpoint of a line that connects a central point on an outer surface of the sidewall that includes the at least one tongue to a central point on an outer surface of the sidewall of the other building element that includes the at least one pair of ridges and is perpendicular to a line that passes through the central points of said interconnected building elements when said building elements are interconnected in a centered configuration .