The Origin of "Eight Eyebrows" in Mathematics

When joking in daily life, people who describe an "eight eyebrows" are "eight points and twenty points".

In fact, when the hour hand and the minute hand on the clock are used to depict the figure of figure eight eyebrows, the two hands should be in a symmetrical position, that is, the two hands should take the lines "6" and "12" on the clock as the symmetry axis, while at 8: 20, the minute hand points to "4" and the hour hand points to the distance between "8" and "9".