Staedtler Mars GmbH & Co. 55981CS Geometry Set, 8 Pieces Packed In Plastic Storage Case Sold as 8/ST. Eight-piece geometry set contains the ideal tools needed for geometry class, including compass, 6" ruler, 180-degree protractor, 45-degree triangle, 60-degree triangle, automatic pencil, eraser and spare leads. Geo set comes neatly packed in a plastic storage case.