Simple demonstration experiments for astronomical parallax

Parallax is the most important astronomical method for determining the distances from the Earth to nearby stars. We present two hands-on activities that explore the concepts and practice of parallax measurement. The first activity is a simple geometrical set-up using simple theodolites, and is accessible for students grade 7 and above. The second activity uses digital photography to recreate astronomical parallax measurements in a classroom setting, and is suitable for students grade 10 and above.
Comment: 7 pages, 12 figures. Published in two parts as "Parallax: reaching the stars with geometry" in Science in School 39, pp. 40-44 (2017) and "Finding the scale of space" in Science in School 40, pp. 40-45 (2017)