It’s easy to overcome that simply by being a bit more precise—you are saying that such and such a proposition is true in geometry X. Meaning that the axioms of geometry X genuinely do imply the proposition. That this proposition may not be true in geometry Y has nothing to do with it.
It is a different sense of true in that it isn’t necessarily related to sensory experience—only to the interrelationships of ideas.
It’s easy to overcome that simply by being a bit more precise—you are saying that such and such a proposition is true in geometry X. Meaning that the axioms of geometry X genuinely do imply the proposition. That this proposition may not be true in geometry Y has nothing to do with it.
It is a different sense of true in that it isn’t necessarily related to sensory experience—only to the interrelationships of ideas.