# `pi`

## Description

Returns the mathematical constant π (pi), limited to 15 decimal places.

## Syntax

```dataprime
pi(): number
```

## Example

**Use case: Compute the area of a circle**

Use π with the formula *π × r²* to calculate the area of a circle given a radius in meters.

### Example data

```json
{
    "distance_m": 10
}
```

### Example query

```dataprime
create area from (pi() * power(distance_m, 2))
```

### Example output

```json
{
    "distance_m": 10,
    "area": 314.1592653589793
}
```