§13.113.
13.
Archimedes Περὶ κωνοειδ. prop. 3 (I p. 272, 23 sqq. ):
Ὃν δὴ λόγον ἔχει τὸ τετράγωνον τὸ ἀπὸ τᾶς ΑΖ ποτὶ τὸ τετράγωνον τὸ ἀπὸ τᾶς ΑΚ, τοῦτον ἐχέτω ἁ Ν ποτὶ τὰν Μ. αἱ δὴ ἀπὸ τᾶς τομᾶς ἐπὶ τὰν ∠Ζ ἀγόμεναι παρὰ τὰν ΑΕ δύνανται τὰ παρὰ τὰν ἴσαν τᾷ Ν παραπίπτοντα πλάτος ἔχοντα, ἃς αὐταὶ ἀπολαμβάνοντι ἀπὸ τᾶς ∠ ποτὶ τὸ ∠ πέρας.
Archimedes, On Conoids and Spheroids, prop. 3 (I, p. 272, 23 sqq.): Let the ratio which the square on AZ has to the square on AK be the ratio which N has to M. Now, the straight lines drawn from the section to ∠Z parallel to AE are equal in square to the areas applied along the line equal to N, having as breadth the segments which they themselves cut off from ∠ towards the end ∠.
δέδεικται γὰρ ἐν τοῖς κωνικοῖς.
For this has been demonstrated in the conics.