A windbreak of 15 m height and 200 m length is established to protect land from wind erosion. The minimum wind velocity at the height of 15 m above the ground required to move the most erodible soil fraction is 9.6 m/s. The wind direction deviates by 20° from the line perpendicular to the windbreak. The area protected by the windbreak is \(\underline{\hspace{2cm}}\) ha.