# PIHALF_DBL

> The mathematical constant (pi / 2). Approximately 1.57. This is a f64/double precision constant.

## Definition

* **Type:** Field
* **Namespace:** [Unity.Mathematics](/engine/6000.6/script-reference/unity/mathematics.md)
* **Assembly:** UnityEngine.MathematicsModule

```csharp
public const double PIHALF_DBL = 1.5707963267948966
```