# Polygon

> Use a convex polygon shape to interpret the PhysicsShape2D geometry.

## Definition

* **Type:** Field
* **Namespace:** [UnityEngine](/engine/6000.7/script-reference/unityengine.md)
* **Assembly:** UnityEngine.Physics2DModule

```csharp
Polygon = 2
```

### Remarks

A polygon geometry type is comprised of a minimum of three (triangle) vertices and maximum defined by [Physics2D.MaxPolygonShapeVertices](/engine/6000.7/script-reference/unityengine/physics2d/maxpolygonshapevertices.md) in the [PhysicsShape2D](/engine/6000.7/script-reference/unityengine/physicsshape2d.md). The vertices represent a set of consecutive edges where each vertex connects to the next vertex with the last vertex automatically representing an edge connecting to the first vertex resulting in a closed primitive shape. These edges must result in a convex polygon. If this is not the case then the physics system will constrain the polygon to be convex by producing a convex hull. All polygon collision detection uses convex polygons for performance reasons.