Ad prop. VI.
λέγεται, ὅσα κατὰ διάμετρον ὄντα ἐν ἴσῳ χρόνω ἴσας περιφερείας διέρχεται καὶ τὸ μὲν ἀπὸ ἀνατολῆς ἐπὶ δύσιν πορεύεται, τὸ δὲ ἀπὸ δύσεως ἐπʼ ἀνατολήν.
ἄρα ἐστὶν ἡ ἀπὸ τοῦ Ε ἐπὶ τὸ Ζ τῇ ἀπὸ τοῦ Β ἐπὶ τὸ Γ. ἐὰν ἄρα ἐπιζεύξωμεν ὡς τὴν ΕΓ καὶ τὴν ΒΖ, αἱ ἐναλλὰξ γωνίαι
αἱ ὑπὸ ΕΓΒ, ΓΕΖ ἴσαι ἀλλήλαις ἔσονται, ὥστε καὶ περιφέρεια ἡ ΕΒ τῇ ΓΖ ἐστιν ἴση. ἐν γὰρ τοῖς ἴσοις κύκλοις αἱ γωνίαι τὸν αὐτὸν
λόγον ἔχουσι τῶν περιφερειῶν, ἐφʼ ὧν βεβήκασιν, ἐάν τε πρὸς τοῖς κύκλοις, ἐάν τε πρὸς ταῖς περιφερείαις ὦσι βεβηκυῖαι.
Scholia in Euclidis phaenomena. Scholia in Euclidem. ed. Heinrich Menge. United States. 2017.
Sponsored by Harvard College Library.
Funding provided by Harvard Library Arcadia Fund.