Surveyors, Engineers, Train railways Expose The Flat Earth?

Chemtrails are level too. They should show curvature if the earth was a ball. Some of those trails are 35,000 feet
Surveyors, engineers and architects are never required to factor the supposed curvature of the Earth into their projects, providing another proof the world is a plane, not a planet. Canals and railways, for example, are always cut and laid horizontally, often over hundreds of miles, without any allowance for curvature.