Latin-American rhythms are a lot of fun to play on the piano because they keep both hands busy -- sometimes playing different rhythms.
But the rhythm of the tango is not as complex as one would think, but because of the interplay between various instruments, one micht get that impression.
There are two basic types of tangos — the Spanish Tango and the Argentine Tango.
The basic structure of the Spanish Tango is in 4/4 with a quarter notes on the first beat followed by an eighth rest on the first half of the 2nd beat followed by two quarter notes in each measure, whereas the Argentine Tango is in 4/4 with three quarter notes followed by 2 eighth notes per measure.
To complicate things a bit, the Spanish Tango sometimes has a two measure rhythm, with the 2nd measure consisting of eighth, quarter, eighth, quarter, quarter.
All this plus many other rhythms are covered in detail in Rhythm Piano.