The other 2-term Machin-like formulas are Euler's Machin-like formula, Hutton's formula, and Machin's formula.
Hermann's Formula
See also
Euler's Machin-Like Formula, Hutton's Formula, Machin's Formula, Machin-Like FormulasExplore with Wolfram|Alpha
Cite this as:
Weisstein, Eric W. "Hermann's Formula." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/HermannsFormula.html