What you have is a skinny, skinny sector of a circle ... like a slice of pie.
The radius of the pie is 427 light-years, and the angle in the center, at
the tip of the slice, is 0.044 second. That's about 0.000012 degree.
The question is: What's the length of the crust out at the fat end of the slice ?
This is a case where it's very handy to measure your angles in radians
instead of degrees. That way, whatever fraction of a radian is at the tip,
the same fraction of the radius is the length of the arc (the crust).
To change degrees to radians, multiply by (pi)/180 .
0.044 second = 0.000012 degree = about 2.133 x 10^-7 radian .
So the diameter of the star is about (2.133 x 10^-7) of 427 light years.
I'll leave that part for you to finish up.
