This model uses a rounded representative diameter of 800 Suns, based on ESO’s description of Betelgeuse as almost 800 times the Sun’s size. It should be read as an approximate illustration, not a precise fixed boundary.
A marble and a much larger world
If the Sun were a 2 cm marble, this Betelgeuse model would be 16 metres across. The arithmetic is exact for the chosen model; the stellar size itself remains uncertain.
When the screen cannot show everything
The Sun becomes less than one drawing unit wide in the side-by-side scene. Its locator marks the position without pretending the disk is larger. Open the Betelgeuse guide for the measurement caveat and source.