ⓘ This interactive app demonstrates a function that finds a circle (gray) that is tangent to, i.e touching, three known circles (red, green, blue). You can drag the known circles around using the mouse or touch. The result is one of the eight solutions to the problem of Apollonius. The function will be a part of a circle packing algorithm. The resulting circle packing can then be applied to data visualization. Maxima was used during formulation. Some ChatGPT was used to generate an empty canvas app. Akseli Palén, 2024.