2 Vintage Triangle wood 12" rulers for drafting, architecture, engineering

Vintage 12" K&E Co Star Quality Triangular Ruler 8881 Three Sided

Dietzgen 1626 Wooden 3-Sided Triangular Ruler Scale Drafting Vintage USA 12" Woo

Vintage Dietzgen 11626 Architect Drafting Triangular Ruler 12" Hardwood Yellow

Wooden 3 Sided Triangle Drafting Ruler Engineer Vintage 12"

Vintage - K&E ( Keuffel & Esser) Drafting Ruler 3 Sided Wood #8895 (712)

Vintage Architect Triangle 3 Sided Drafting Ruler Scale POST 1301P Made in USA

Vintage Wooden Triangular Architect Drafting Ruler 12" 3-Sided Made In England