Pi

π (greek letter pi) is the ratio of the circumference of a circle to its diameter. π is about 3.14159265358979. A full circle has 2*pi() radians.

In Free Pascal's RTL, system.pi is a function which returns the value of π. This allows you to assign addr(system.pi) to a procedural variable.

pi()/4 is the same as arctan(1).

See also

• system.pi
• system.arctan calculates arc tangent.

---

From the Free Pascal wiki, page "Pi", as it stood on 2022-08-06 after a change by Kai Burghardt, out of the wiki's dump of 2024-05-26. Copyright stays with the author who wrote it, according to the old wiki's Licensing page. If you have concerns about this material, message the admin.