> For the complete documentation index, see [llms.txt](https://help.trikset.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://help.trikset.com/en/studio/programming-visual/expression-syntax/const.md).

# Constants

TRIK Studio has only one built-in constant. It can be used in the same way as [sensor variables](/en/studio/programming-visual/expression-syntax/sensory-variables.md), but its value cannot be changed.

|        |                  |                                                                                                      |
| ------ | ---------------- | ---------------------------------------------------------------------------------------------------- |
| **pi** | 3.14159265358979 | Represents the ratio of the circumference of a circle to its diameter, determined by the constant π. |