All three are Chinese Empire, as are the vast majority of coins of this style. All of these are from the same time period, the reign of the
Qian Long emperor (1735-1796 AD). The coins can't be dated any more precisely than that.
The "obverse" of these coins is the side with the four Chinese characters. "Right way up" for the obverse has at the top the character with the "Z" shape on the right side.
The reverse is in Manchu script, which looks kind of like Arabic, only sideways. "Right way up" has the word with the three loops ("boo", meaning "mint") on the left side. The other word on the reverse is the "mintmark".
As for your coins: 1 and 3 are the same: Board of Revenue mint in the capital, Beijing. Number 2 is from the provincial mint of Baoding (Paoting), Zhili (Chihli) province, just to the southwest of Beijing. This emperor had around 20 mints throughout the empire, and assembling a complete mintmark collection can be challenging, yet inexpensive.
Don't say "infinitely" when you mean "very"; otherwise, you'll have no word left when you want to talk about something really infinite. - C. S. Lewis