One way to calculate the distance between Earth and a nearby star is to measure the angle

Question:

One way to calculate the distance between Earth and a nearby star is to measure the angle between the star and the ecliptic (the plane of Earth's orbit) at 6-month intervals. A star is measured at a 42.13204° angle. Six months later, the angle is 42.13226°. The diameter of Earth's orbit is 3.13 10-5 light-years. What is the distance to the star at the time of each reading? Use this diagram to help you solve this problem.