3.Isoperimetric inequality for sphere and ellipsoid is discussed, and the isoperimetric inequality of some region satisfying certain conditions is given.
10.Ecuador's monument to the equator is 240m off, and the circumference of the ellipsoid that best matches Earth's actual shape isn't a perfect 40,000km.
11.These dense lumps of rock bump out from the ellipsoid and their mass gravitationally attracts oceans, while valleys in the ocean floor have less mass and the oceans flow away, shallower.
12.This is the ellipsoid we used today, the one that's published by the National Geospatial Intelligence Agency And it's the foundation of the coordinate system used by GPS.
13.And then with a bunch of trigonometry, they could figure out the distance from A to B. And this sort of arduous process proved that, yeah, the Earth was an ellipsoid.