Question 295709
Well first off, geometric proofs need support, so we can quickly cross off the last choice. If they didn't need support, then we could claim anything (whether it's true or not).



For the first choice, geometry doesn't really deal with experiments. So we can ignore this choice. For the second, measurement is used in geometry, but not necessarily in proofs. So we can ignore this one as well. 


It turns out that the answer is the third choice as geometry is essentially built on other proven theorems, axioms, and definitions.