This is one of several challenges left for the community by Calvin's Hobbies. The curve that an idealised hanging rope or chain makes is a catenary. Image by Bin im Garten, via Wikimedia Commons.
CROSBY 5/8 MISSING LINK G335 (1013236)
CROSBY 1013192 G-335 Missing Link | 1/2-Inch Galvanized Replacement Connecting Link | 4,750 Lb. Working Load Limit | Quenched and Tempered Forged
Transport Systems
geometry - Finding the catenary curve through three given points
リース契約可能】GAUSIUM(ガウシウム)チャージングステーション
US Navy Course Boatswains Mate NAVEDTRA 14343, PDF
code golf - Make America(n Maps) Great Again - Code Golf Stack
Transient Systems by Emergent Technologies and Design [EmTech
code challenge - Travelling Salesman - Code Golf Stack Exchange
Trail Terms - American Trails
リース契約可能】GAUSIUM(ガウシウム)チャージングステーション