Given the Force, $\overrightarrow F$ and Distance $\overrightarrow D$ vectors, we can write the work done as $\overrightarrow W = \overrightarrow F \times \overrightarrow D$
$\overrightarrow a.\overrightarrow b=|\overrightarrow a|\:|\overrightarrow b|\:cos\theta$
$\Rightarrow$$\;\overrightarrow W = \overrightarrow F \times \overrightarrow D = | \overrightarrow F| \times |\overrightarrow D| \times \cos \theta$
In our case $\theta = 30 ^{0} = \large\frac{\pi}{6}$
$\Rightarrow$$\;\overrightarrow W = | \overrightarrow F| \times |\overrightarrow D| \times \cos \theta = 1500N \times 1000m \times \cos \large(\frac{\pi}{6})$
$\Rightarrow \overrightarrow W = 750000 \sqrt 3 J \approx 1299038 J$