The surface distance from the North Pole to the Equator is 10,011.720km. For this point, we're only going to use the Northern Hemisphere.
The circumference at the equator is 40,075.02km.
Using the formula 2*Pi*r=Circumference however, the circumference on a flat Earth would be 62,905.492km
FE Equatorial circumference=62,905.49km (38,087.66 miles) while the actual measured circumference is 40,075.02km (24,901.46),
a difference of 22830.47km (14186.20 miles).
Therefore the Flat Earth is proven impossible.