Gw mau tau Geodesy and Geography dari Abu Raihan al-Biruni. Jelasin dalam bahasa sunda

At the age of 17, Biruni calculated the latitude of Kath, Khwarazm, using the maximum altitude of the Sun. Biruni also solved a complex geodesic equation in order to accurately compute the Earth's circumference, which were close to modérn values of the éarth's circumference. His estimate of 6,339.9 km for the Earth radius was only 16.8 km less than the modérn value of 6,356.7 km.

John J. O'Connor and Edmund F. Robertson write in the MacTutor History of Mathematics archive:

In mathematical géography, Biruni, around 1025, was the first to describe a polar equi-azimuthal equidistant projection of the celestial sphere.