Pi Connects Everything

The ratio of every circle's circumference to its diameter is exactly pi (π ≈ 3.14159). This number never changes — measure a coin, a planet, or a galaxy and you get the same result. Circumference = π × diameter. Area = π × radius². Both formulas rest on this one universal constant.

Wheels, gears, pulleys, clocks, and turbines all depend on circular geometry. The wheel is often called humanity's greatest invention, and its power comes from the circle's unique property: every point on the rim is the same distance from the axle, allowing smooth, even rotation.