It is known or found that three edges are 3, 3, 4,
There are three more? +3? ≠4? Therefore, it is not a right triangle, so you can't find tanB with the opposite side, adjacent side and hypotenuse.
You have to use the same angle trigonometric function relationship to find it.
Cosb = 1/9 has been found. Use sin? B+cos? B= 1
Available sinb = 4 √ 5/9
Then use sinb/cosb = tanb.
Available tanb = 4 √ 5