History of mathematical notation back to any school or period before that of the Ionian Greeks, but the subsequent history may be divided into periods, the distinctions between which are tolerably well marked. Greek mathematics, which originated with the study of geometry, tended from its commencement to be deductive and scientific. Since the fourth century AD, Pythagoras has commonly been given credit for discovering the Pythagorean theorem, a theorem in geometry that states that in a right-angled triangle the area of the square on the hypotenuse (the side opposite the right angle) is equal to the sum of the areas of the squares of
Jessie (given name) are Jane/Joan (Sìne), Janie (Sìneag), and Janet/Janice (Seònaid); though spelling may change slightly dependent upon the form of Gaelic (Irish or Scottish). An additional nickname for Jessie, heard in Scotland, is Jinty (or Jinny), a connection to Jean (female given name)/Jane/Jennie. Jessie is as an Anglicisation of the Gaelic root-word of "seas", meaning "to stand". In Irish Gaelige this is Seasaidh/Seasaídh (pro. "Sheh-see", emphasis on first syllable), which uses the fut. aff. conjugation of "seas". The Scots Gàidhlig variant is Seasaidh/Teasaidh/Teasag, (pronounced "Cheh-say"). Jessie (given name) Jessie is a given name in its own right, but may also be a