University of Tehran Press Journal for the History of Science 1735-0573 2 1 2004 11 21 - - 11486 FA Journal Article Eucilds priniciples which contains thirteen articles in geometry was transferred to Islamic world via two translations entitled haruni and ma muni . the geometry books of Islamic era contains two additional articles by hypsicles . Avicenna compild the chapter of geometry of shifa on the basis of these fifteen articles .and presented his own reasoning. In order to be familiar with Avicenna s method of reasoning . the proposition of cutting a certain line in exrtain line in extreme and mean ratio will be discussed in this article Eucilds priniciples which contains thirteen articles in geometry was transferred to Islamic world via two translations entitled haruni and ma muni . the geometry books of Islamic era contains two additional articles by hypsicles . Avicenna compild the chapter of geometry of shifa on the basis of these fifteen articles .and presented his own reasoning. In order to be familiar with Avicenna s method of reasoning . the proposition of cutting a certain line in exrtain line in extreme and mean ratio will be discussed in this article https://jihs.ut.ac.ir/article_11486_570badcfe14697bf2a244e2e25b93e59.pdf