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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