## Trigonometry 7th Edition

$2.11$ radians
First convert the angle to decimal degrees: $120^{\circ}40'=120^{\circ}+(\frac{40}{60})^{\circ}=120.67^{\circ}$. Now convert to radians: $120.67^{\circ}=120.67(\frac{\pi}{180})\approx2.11$ radians.