What is the largest possible number of reflex angles in a decagon?

Is there a faster way? or easier way to this?

The sum of a decagon's angles must be 180*(10-2) = 180*8 = 1440

1440 is exactly 180*8 and since reflex angles are greater than 180, there can't be 8 or higher reflex angles, that doesn't rule out 7 though, and I'm sure you can find a decagon with 7 reflex angles.