It depends if that angle is in degrees or radians; let's assume radians because then there's a trick.
If we draw the line from the star to the sun, we have a right triangle, angle .000302/2, opposite 1 AU and hypotenuse x the distance we seek.
[tex] \sin \dfrac{.000302}{2} = \dfrac{1}{x}[/tex]
The trick is for really small angles the sine is (approximately) equal to the angle in radians:
[tex] x = 2/.000302 = 6622.52 \textrm{ AU}[/tex]
Let's see if our approximation made a difference in the last digit:
[tex] x = 1/\sin(.000302/2) = 6622.52\textrm{ AU}[/tex]
Nope, no difference to six sig figs.
Answer: 6623
