Is the T=2*q*A Formula Valid for Both Open and Closed Thin-Walled Members?

[aerosiyar]

is T=2*q*A formuala valid for both open thin-walled and closed thin-walled members, where T is torque, q is shear flow, and A is the Area.

 

[Chestermiller]

is T=2*q*A formuala valid for both open thin-walled and closed thin-walled members, where T is torque, q is shear flow, and A is the Area.

Are there no physical properties involved?