Parses a string expression representing an angle into a number. Supports mathematical constants (pi) and functions (sin, cos).
The angle expression (e.g., "pi/2", "0.785") or a number.
The parsed angle in radians.
If the angle parameter is missing or the expression is invalid.
Parses a string expression representing an angle into a number. Supports mathematical constants (pi) and functions (sin, cos).