940 millimeter = 37.007 874 016 inch or just over 3 feet in Length. As to what points this particular manufacturer picks to measure from, who knows?
The "180" in the name of the plane is the model of REAL Cessna the plane is emulating and has absolutely nothing to do with its size. A Cessna 182 is the same basic plane but in Tri-cycle landing gear. Cessna also makes a "170" version which is slightly smaller.(other differences too but not needed in this discussion)

Alot of these cheap toys don't last long enough to need parts but I'd recommend contacting [email protected] and asking them about it.