# CircleEquation struct

Namespace: [Grasshopper2.Eto.Drawing](https://developer.rhino3d.com/api/gh2/namespace/grasshopper2.eto.drawing.md) · Assembly: [Grasshopper2](https://developer.rhino3d.com/api/gh2/assembly/grasshopper2.md)

```cs
public readonly struct CircleEquation
```

Represents the implicit equation of a circle.

## Constructors

- [CircleEquation](https://developer.rhino3d.com/api/gh2/type/grasshopper2.eto.drawing.circleequation/ctor.md): Construct a new circle equation.

## Methods

- [Evaluate](https://developer.rhino3d.com/api/gh2/type/grasshopper2.eto.drawing.circleequation/evaluate.md): Evaluate a coordinate pair. Zero scalar reside on the circle, negative values are inside the circle. The centre of the circle is associated with the most negative value of -(radius²).
- [ToString](https://developer.rhino3d.com/api/gh2/type/grasshopper2.eto.drawing.circleequation/tostring.md): Returns the fully qualified type name of this instance.