Math Central on Instagram: "Pi (π) is a mathematical constant representing the ratio of a circle’s circumference to its diameter. It’s an irrational number, meaning it has an infinite, non-repeating decimal expansion. The approximate value of pi is 3.14159, but it continues infinitely. Pi is essential in geometry, trigonometry, and many other fields, particularly when dealing with circles, spheres, and periodic functions. Follow @themathcentral for more!"