?????? Cos ?? I don’t know the difference between cos and tan fully yet , but ASAP help here

The answer is M
Step-by-step explanation:
Cosine: this is the length of the side right next to the angle divided by the longest side/ hypotenuse.
Tan: this is the length of the side opposite of the angle divided by the side directly adjacent/ next to the angle.
In this case, cosine would be 6/10 which Is also 3/5. the angle right next to 6 is Angle M