Construx Building Toys - 1980s

From Wikipedia: Construx is a brand of plastic building toys introduced by Fisher-Price in 1983. Unlike other building toys such as <a popular brick building toy>, Construx feature beam-like pieces of varying lengths that snapped on to cubical connector knots in order to build large shapes. These are relatively secure even though no nuts or bolts were used. Panels allowed assembly of flat surfaces. Hinges, motors, wheels, and other movable parts expand the number of different shapes