Net Work Done By Torques

Three torques are applied to a rigid wheel: $\tau_1 = 4.0\ \mathrm{N \cdot m}$ at an angle of $0^\circ$, $\tau_2 = 3.0\ \mathrm{N \cdot m}$ at $90^\circ$, and $\tau_3 = 5.0\ \mathrm{N \cdot m}$ at $270^\circ$. If the wheel undergoes an angular displacement of 1.5 radians in the $0^\circ$ direction, what is the net work done by the torques?