modeling-app/docs/kcl-std/functions/std-sketch-involuteCircular.md

---
title: "involuteCircular"
subtitle: "Function in std::sketch"
excerpt: "Extend the current sketch with a new involute circular curve."
layout: manual
---

Extend the current sketch with a new involute circular curve.

```kcl
involuteCircular(
  @sketch: Sketch,
  angle: number(Angle),
  startRadius?: number(Length),
  endRadius?: number(Length),
  startDiameter?: number(Length),
  endDiameter?: number(Length),
  reverse?: bool,
  tag?: TagDecl,
): Sketch
```



### Arguments

| Name | Type | Description | Required |
|----------|------|-------------|----------|
| `sketch` | [`Sketch`](/docs/kcl-std/types/std-types-Sketch) | Which sketch should this path be added to? | Yes |
| `angle` | [`number(Angle)`](/docs/kcl-std/types/std-types-number) | The angle to rotate the involute by. A value of zero will produce a curve with a tangent along the x-axis at the start point of the curve. | Yes |
| `startRadius` | [`number(Length)`](/docs/kcl-std/types/std-types-number) | The involute is described between two circles, startRadius is the radius of the inner circle. Either `startRadius` or `startDiameter` must be given (but not both). | No |
| `endRadius` | [`number(Length)`](/docs/kcl-std/types/std-types-number) | The involute is described between two circles, endRadius is the radius of the outer circle. Either `endRadius` or `endDiameter` must be given (but not both). | No |
| `startDiameter` | [`number(Length)`](/docs/kcl-std/types/std-types-number) | The involute is described between two circles, startDiameter describes the inner circle. Either `startRadius` or `startDiameter` must be given (but not both). | No |
| `endDiameter` | [`number(Length)`](/docs/kcl-std/types/std-types-number) | The involute is described between two circles, endDiameter describes the outer circle. Either `endRadius` or `endDiameter` must be given (but not both). | No |
| `reverse` | [`bool`](/docs/kcl-std/types/std-types-bool) | If reverse is true, the segment will start from the end of the involute, otherwise it will start from that start. | No |
| `tag` | [`TagDecl`](/docs/kcl-std/types/std-types-TagDecl) | Create a new tag which refers to this line. | No |

### Returns

[`Sketch`](/docs/kcl-std/types/std-types-Sketch) - A sketch is a collection of paths.


### Examples

```kcl
a = 10
b = 14
startSketchOn(XZ)
  |> startProfile(at = [0, 0])
  |> involuteCircular(startRadius = a, endRadius = b, angle = 60deg)
  |> involuteCircular(
       startRadius = a,
       endRadius = b,
       angle = 60deg,
       reverse = true,
     )

```

![Rendered example of involuteCircular 0](data:image/png;base64,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