The tangent ratio is the ratio of the side the acute angle over the side to the acute angle. opposite, adjacent opposite, hypotenuse adjacent, hypotenuse adjacent, opposite

For this case what you have to take into account is the following trigonometric definition:
 Tan (x) = (C.O) / (C.A) 
 Where,
 x: angle
 C.O: opposite leg
 C.A: Adjacent cateto.
 We have then:
 The tangent ratio is the ratio of the side opposite the angle of the side to the angle.
  
 opposite, adjacent