Tangent ratio is the ratio between the opposite and the adjacent sides to given angle.
It depends on the given angle to stablish which is the adjacent and which is the opposite side.
For example, for the angle that measures 12°, the opposite side is the one that measures x and the adjacent is the one that measures 6, it means:
For the other angle, the one that measures 78, the opposite side now is the one that measures 6 and the adjacent is the one that measures x, it means:
It means that both Andre and Mai are correct.