# Optica μγ΄.

Euclid, Optica, μγ΄.. Ancient Greek.

Canonical: https://interlinea.aeterna-institute.org/library/greek/euclid/optica/%CE%BC%CE%B3%CE%84.

Τὸ δ᾿ αὐτὸ συμβήσεται, κἂν παράλληλος ᾖ ἡ εὐθεῖα γραμμὴ τῷ ὁρωμένῳ μεγέθει. ἔστω ὁρώμενον μέγεθος τὸ ΑΒ καὶ τετμήσθω δίχα κατὰ τὸ Ε σημεῖον, καὶ ἀνήχθω ἀπὸ τοῦ Ε τῇ ΑΒ πρὸς ὀρθὰς ἡ ΕΖ, ἐφ᾿ ἧς ὄμμα κείσθω τὸ Ζ, καὶ ἐπεζεύχθωσαν εὐθεῖαι αἱ ΖΑ, ΖΒ, καὶ περιγεγράφθω περὶ τὸ ΑΖΒ τρίγωνον τμῆμα τὸ ΑΖΒ, καὶ ἤχθω διὰ τοῦ Ζ τῇ ΑΒ παράλληλος ἡ Ζ∠, καὶ μετακείσθω τὸ ὄμμα ἐπὶ τὸ ∠, καὶ προσπιπτέτωσαν ἀκτῖνες αἱ Α∠, ∠Β. λέγω, ὅτι ἀπὸ τῶν ∠, Ζ ἄνισα φανήσεται. ἐπεζεύχθω ἡ ΑΗ. ἐπεὶ οὖν ἴση γωνία ἡ ὑπὸ ΑΖΒ τῇ ὑπὸ ΑΗΒ, ἀλλ᾿ ἡ ὑπὸ ΑΗΒ τῆς ὑπὸ Α∠Β μείζων ἐστίν, καὶ ἡ ὑπὸ ΑΖΒ ἄρα τῆς ὑπὸ Α∠Β μείζων ἐστίν. καὶ ὑπὸ μὲν τῆς ὑπὸ ΑΖΒ τὸ ΑΒ βλέπεται τοῦ ὄμματος ἐπὶ τοῦ Ζ ὄντος, ὁμοίως δὲ καὶ ὑπὸ τῆς ὑπὸ Α∠Β ἐπὶ τοῦ ∠ ὄντος. ἄνισον ἄρα τὸ ὁρώμενον φαίνεται ἀπὸ τῶν ∠, Ζ. καὶ ἐὰν τεθῇ ἴση τῇ ∠Ζ ἡ ΖΓ, ἔλαττον μὲν καὶ ἀπὸ τοῦ Γ φαίνεται ἤπερ ἀπὸ τοῦ Ζ, ἀπὸ δὲ τῶν Γ, ∠ ἴσον.

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Euclid, Optica, ed. Johan Ludvig Heiberg, Heinrich Menge. Text: The Greek Library, from the Perseus Digital Library and other open sources, CC BY-SA 4.0. Changes: apostrophes normalised and the text divided into reading sections by Interlinea.
License: CC BY-SA 4.0 (https://creativecommons.org/licenses/by-sa/4.0/). Source: https://thegreeklibrary.pages.lisn.upsaclay.fr/works/tlg1799.tlg009.local001/.