What mathematical formula was used to create pi?

Pi (π) is not derived from a single mathematical formula but is often approximated using various methods. One of the most famous formulas is the Leibniz formula for π, which states that π can be calculated as π = 4 * (1 - 1/3 + 1/5 - 1/7 + 1/9 - ...). Another notable method is the use of the circumference-to-diameter ratio of a circle, which defines pi as the constant ratio. Additionally, more complex series and products, such as the Bailey-Borwein-Plouffe formula, also provide ways to calculate π.