There were two layers of curtains covering the mishkan. The first layer was made of colored wools and the second layer was made from goat hair. The second layer was made with great wisdom bc they somehow spun the hair into threads while the hair was still attached to the goats.

We learn the size of reshus harabim- 16 Amos wide- from the wagons used in the desert to transport the kerashim. There were two rows of wagons. Each wagon took up 5 Amos (2 and 1/2 wide, + 1 1/4 per wheels) and there was 5 Amos space between wagons. Plus one xtra amma bc a Levi stood on side of the wagons to make sure boards didn’t fall

A big rock in the street - 10 tefachim high and 4 tefachim wide- is a reshus hayachid. Similarly, a pit 10 tefach deep and 4 tefach wide is a reshus hayachid.

The banks of a pit can combine in height with the walls of the inside pit to make a total height of 10 tefachim so the pit would be a reshus hayachid.

A wall that is 10 tefach high but not 4 tefach wide could be a reshus hayachid if it encloses another domain. This is logical: “if it makes another domain a reshus hayachid, certainly it itself is a reshus hayachid!”

If there’s a pit 9 tefach deep and someone takes out a tefach worth of dirt, the gemara is unsure if they’re liable. The akira of the item is simultaneous with the creation of the reshus hayachid. Similarly, what if someone places down dirt in a pit exactly 10 tefach deep? The hanacha is simultaneous with the removal of the status of reshus hayachid. However, this question is only bc dirt is a material one leaves permanently in the pit. But a random item wouldn’t detract from the size and one would be liable for putting it in 10 tefach pit.

Another similar question is if someone throws a four tefach board on top of a 10 tefach board in a street, where the item will be completing the status of the reshus hayachid. And if in this case one is exempt bc the time is first completing the Reshus hayachid, the gemara adds a safek if the board had another item on top. Maybe there it takes another moment before the top item will “land” and settle on top of the board and reshus will already be in place.