I'm sorry, but have you thought this through? Real-world ropes flex and bend, which alone causes experimental error orders of magnitude larger than one in a mi

I'm sorry, but have you thought this through? Real-world ropes flex and bend, which alone causes experimental error orders of magnitude larger than one in a million. There does not exist a rope material that doesn't flex at least one millimeter per a km of rope, and certainly did not exist 6000 years ago. Hell, even if we assume a perfectly flat plain, the curvature of Earth would cause an error larger than 1e-6. And obviously if you try to hang the rope from both ends and pull it taut, it will flex and it's also impossible to remove all the slack. You need a laser, or at least something like the Michelson–Morley experiment, exploiting the wave nature of light, to measure any real-world distance to the precision required. And obviously for that to work, you also need to know the speed of light to the same precision. And given that we're not in a vacuum, even light bends as it travels through air, especially air near the ground. You know heat haze? Yeah, that's going to mess up your experiment too. And how on Earth would they ensure the ropes form a right angle to a precision of one in a million? Given a 1km long side, the sideways margin of error is again 1mm. The angular precision needed is sub-arcsecond, a resolution that you need a large-ish optical telescope to achieve. And obviously then there's the question of measuring the length of the hypothenuse.