Once in Cambodia I went to a buddhist temple. On the stone walls some depictions of the buda had him holding a measuring square - I was like, who would have thought buda would be interested in Pythagorean affairs.

Potentially feasible alternate interpretation: given that the Indian religious / ruling caste in Cambodia who brought Hinduism and Buddhism had arrived by boat and were sophisticated seafarers there is a chance this would be an astronomic device rather than a geometric tool for ground-based construction. The only reference I can find in the Pali texts to construction whatsoever is negative referring to undesirable mental habits, ie. https://www.accesstoinsight.org/tipitaka/kn/dhp/dhp.11.than.... House-builder, you're seen! You will not build a house again. All your rafters broken, the ridge pole dismantled, immersed in dismantling, the mind has attained to the end of craving. (See https://en.wikipedia.org/wiki/Sa%E1%B9%85kh%C4%81ra for interpretation)

PS. If you ever get the chance to compare parts of Cambodian hinterland (eg. area around Battambang) with South India (eg. western Tamil Nadu) you will realise they bear a striking topographic resemblance: vast tropical plains punctuated by extremely vertical mountains. Beautiful setting for settled agriculture.

Construction of sites for Yajna[0] and specifically, the Yajna Vedi[1] where the central fire was located, required precision and mathematical calculations[2]. Based on the origins of Hinduism/Buddhism, I'll not be surprised if instruments of calculation were common in religious affairs.

[0]: https://en.wikipedia.org/wiki/Yajna

[1]: https://en.wikipedia.org/wiki/Vedi_(altar)

[2]: http://ijyr.dsvv.ac.in/index.php/ijyr/article/view/50/101

Sure, there's a lot of mathematical mysticism in India and I have seen this at Jain sites. However, the Buddha subject would suggest a Buddhist reference. My recollection is that Cambodian sites with bitraditional syncretism were periodically built out or converted between the two traditions - not constructed blended, ie. a Buddha figure would not be carved with a Hindu item.

Yes, you can see it in the temples as well, even the buddhist ones use the Hindu style with straight lines instead of the round stupas.

I think that particular stone carving was recent(ish) but might be wrong. It was a very small local wat and I think I went into it randomly while walking around - the depiction didn't felt buddhist nor hindu at all, if anything it looked masonic or automatically generated from a set of symbols.

Any other clues for how to find this? I'd love to see a Pythagorean buddha.

In siem reap on the main road, that goes to the city when you come from the airport, there's a few temples close to the city. If I'm remembering correctly (+6 years ago), it will be in one on the right side of the road (coming into the city), black stone walls. I had a picture of it but can't find it, typical buddha pose, halo like around the head, but instead of resting hands on the lap it was holding the square.

Maybe the budha was a mason

> a measuring square

Obviously was a smartphone, given by the extraterrestrials who helped constructing that temple and pyramids.

Probably they have a web app to turn on and off the obelisk at DC.