Euclid Book 1
Proposition 28
Theorem
Statement A
[an error occurred while processing this directive]
Statement B
[an error occurred while processing this directive]
Original statement
ἐὰν ϵἰς δύο ϵὐθϵίας ϵὐθϵῖα ἐμπίπτουσα τὴν ἐκτὸς γωνίαν τῇ ἐντὸς καὶ ἀπϵναντίον καὶ ἐπὶ τὰ αὐτὰ μέρη ἴσην ποιῇ ἢ τὰς ἐντὸς καὶ ἐπὶ τὰ αὐτὰ μέρη δυσὶν ὀρθαῖς ἴσας, παράλληλοι ἔσονται ἀλλήλαις αἱ ϵὐθϵῖαι.
English translation
If a straight line falling on two straight lines make the exterior angle equal to the interior and opposite angle on the same side, or the interior angles on the same side equal to two right angles, the straight lines will be parallel to one another.
Computable version A
[an error occurred while processing this directive]
Computable version B
[an error occurred while processing this directive]
Additional instances
[an error occurred while processing this directive]
Proof outline
[an error occurred while processing this directive]
Dependency graphs
[an error occurred while processing this directive]