📒 a flat shape with three straight sides and three angles; a thing in the shape of a triangle
📒 a simple musical instrument that consists of a long piece of metal bent into the shape of a triangle, that you hit with another piece of metal
📒 a situation involving three people in a complicated relationship
📒 an instrument for drawing straight lines and angles, made from a flat piece of plastic or metal in the shape of a triangle with one angle of 90°