By using a leafstone but it is good you trainded it to such a high level cause now it knows all the moves it can't learn after evolution ;) good job!!
You have to trade it.
level 40.
It evolves at Level 30
train it to level 40
tangela does not have an evolution
17
Tangela will only evolve if you level it up once it knows ancient power (which it learns at level 33). take it to the move maniac to make it learn it if you didn't teach it to tangela.
Tangela > level up while knowing Ancientpower > Tangrowth
Tangela evolves when it learns the attack Ancient Powerand then Levels up.
High friendship between 4am between 8pm
Tangela has to level up while knowing the move Ancientpower.
yes keep on doing macthes and you will get leveld up and if you get leveled up a bunch of times you might elvole(elvole means somthing changed )