Use `=PI()` to return the value of pi
Multiply `PI()` by a radius squared to calculate the area of a circle: `=PI()*A1^2`
Multiply `PI()` by diameter to calculate circumference: `=PI()*A1`
Use `PI()` in formulas for spheres, cylinders, and other circular calculations
Combine `PI()` with trigonometric functions like `SIN()`, `COS()`, and `TAN()`
Use `PI()` in angle conversions, such as radians: `=degrees*PI()/180`
Reference `PI()` inside other formulas instead of typing a decimal approximation
Format the result cell as needed for display precision