You can derive pi/4 from summing alternating reciprocals of odd numbers. No geometry. You do need limits (since pi is transcendental, there are no purely algebr

You can derive pi/4 from summing alternating reciprocals of odd numbers. No geometry. You do need limits (since pi is transcendental, there are no purely algebraic solutions. You can use special functions, but those have limits or other transcendentals "in them"). https://en.wikipedia.org/wiki/Leibniz_formula_for_%CF%80 https://en.wikipedia.org/wiki/Leibniz_formula_for_%CF%80