Answer
The power dissipated by the bulb is $0.987~W$
Work Step by Step
When the angle is $20.0^{\circ}$, the amount of power received by the antenna will be reduced by a factor of $cos~20.0^{\circ}$. We can find the power dissipated by the bulb:
$P' = (1.05~W)~cos~20.0^{\circ} = 0.987~W$
The power dissipated by the bulb is $0.987~W$