# Scholia in opticorum recensionem Theonis (scholia vetera) 69

Scholia in Euclidem, Scholia in opticorum recensionem Theonis (scholia vetera), Section 69. Ancient Greek.

Canonical: https://interlinea.aeterna-institute.org/library/greek/scholia-in-euclidem/scholia-in-opticorum-recensionem-theonis-scholia-vetera/69

69. Ἐπὶ τὴν κοινὴν ἄρα p. 208, ἔχομεν γὰρ ἐν τοῖς Στερεοῖς θεώρημα· ἐὰν ἐπίπεδον πρὸς ἐπίπεδον ὀρθὸν ᾖ, καὶ ἀπό τινος σημείου αὐτῶν ἐν ἑνὶ τῶν ἐπιπέδων ἐπὶ τὸ ἕτερον ἐπίπεδον κάθετος ἀχθῇ, ἐπὶ τῆς κοινῆς τομῆς πεσεῖται τῶν ἐπιπέδων.

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Scholia in Euclidem, Scholia in opticorum recensionem Theonis (scholia vetera), ed. Johan Ludvig Heiberg, H. 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/tlg5022.tlg004.local001/.