Make the number π look sexier by expressing it equivalently or approximately in an expression of numbers or/and constants—for example, π = 1 – 1/3 + 1/5 – 1/7 + 1/9 – 1/11 + ⋯, π ≈ √2 + √3, π⁴ + π⁵ ≈ e⁶, and π rad = 180°.
by MathPlus October 15, 2021