by Karly Wilhau
Euclid wrote a textbook on geometry called the Elements. This method is assuming a small set of starting points and combining other theorems. So a small number of starting points create a straight line. He also says all right angles are equal to each other. His propositions begin with plane geometry and are taught in middle school and that geometry uses three dimensions. Most of his book has answers that are now used in algebra and number theory.