He is the father of spherical astronomy, by which the location of objects like planets and stars in the universe can be determined.
Geometry
He wrote a text on spherical geometry.
Pythagoras and Euclid were best known for their work in mathematics.
That's part of the field of Astronomy.
natural philosophy, botany, astronomy and more.
Astronomy.
Johannes' field of study was astronomy and mathematics.
Euclid wrote "The Elements", in which he made many rules that define the geometry taught in schools today.
Hippocrates and Euclid made their greatest achievements in the fields of Mathematics, Medicine, and Engineering.
That's part of the field of Astronomy.
he specialized in the field of astronomy.
astronomy