samanfatma (25)in #euclidpostulates • last yearRE: Why did Euclid prove his first four postulates? Why didn't he prove his fifth postulate (parallelism)?thank yousteem.history (77)in #introducemyself • last yearRE: Introduce my selfHello welcome to Steemit world! I'm @steem.history, who is steem witness. This is a recommended post for you.…