The sheet-metal worker's guide : a practical handbook for tinsmiths, coppersmiths, zincworkers, etc., comprising numerous geometrical diagrams and working patterns, with descriptive text (1888)
Crane, W. J. E. (W. J. Eden) · London : Lockwood and Son · leaf 63
5] POLYHEDRONS. form a solid angle, it follows that the most elementary and simple of the solids is a pyramid … Fig. 46. whose base is triangular, and whose sides are formed by three triangles, which unite in the angle at the apex, or top, of the pyramid. D 2
Sheet-metal work
Internet Archive · Getty Research Institute · Public domain (published before 1931). Free to use for anything.
![An illustration from M. Vitrvvii viri svae professionis pertissimi De architectvra libri decem, ad Avgvstum Cæsarem accuratiss. conscripsit & nvnc primvm in Germania qva potuit diligentia excusi, atq[ue] hinc inde schematibus non iniucundis exornati (1543)](https://img.insideoutlibrary.com/img/200/ia-mvitrvviivirisva00vitr-96-25.webp)
