Go to :
File >> Settings >> Editor >> Colors & Fonts >> Font
When your Android Studio uses the Default Scheme you Can't Edit the Font in Editor Font Section
1 : Save as the Default Scheme by Every Name you Want
Now You Can Pick a Font
2 : Unchecked the Show only monospaced font
3 : in Primary Font Spinner , Chose Tahoma
4 : Set Size and Line Spacing You Want
5 : Apply and Ok