Spreadsheet with other people’s measurements as well as mine:

https://docs.google.com/spreadsheets/d/1jsoWsu1ZmLkedRxiHok-2Xpk44d-bu4Ci2cOr81Ke2c/edit?usp=sharing

Length of shadow:
120 7/8 inches = 3.070225 meters

Height of pole:
50 1/8 inches = 1.274445 meters

angle = arctangent ( p / s )

Where:
p is the length of the pole
s is the length of the shadow

angle = arctan ( 1.274445 / 3.070225) = 22.54325°