---
title: "addRelativeArc(center:radius:startAngle:delta:transform:)"
framework: swiftui
role: symbol
role_heading: Instance Method
path: "swiftui/path/addrelativearc(center:radius:startangle:delta:transform:)"
---

# addRelativeArc(center:radius:startAngle:delta:transform:)

Adds an arc of a circle to the path, specified with a radius and a difference in angle.

## Declaration

```swift
mutating func addRelativeArc(center: CGPoint, radius: CGFloat, startAngle: Angle, delta: Angle, transform: CGAffineTransform = .identity)
```

## Parameters

- `center`: The center of the arc, in user space coordinates.
- `radius`: The radius of the arc, in user space coordinates.
- `startAngle`: The angle to the starting point of the arc, measured from the positive x-axis.
- `delta`: The difference between the starting angle and ending angle of the arc. A positive value creates a counter- clockwise arc (in user space coordinates), and vice versa.
- `transform`: An affine transform to apply to the arc before adding to the path. Defaults to the identity transform if not specified. /

## Discussion

Discussion This method calculates starting and ending points using the radius and angles you specify, uses a sequence of cubic Bézier curves to approximate a segment of a circle between those points, and then appends those curves to the path. The delta parameter determines both the length of the arc the direction in which the arc is created; the actual direction of the final path is dependent on the transform parameter and the current transform of a context where the path is drawn. However, because SwiftUI by default uses a vertically-flipped coordinate system (with the origin in the top-left of the view), specifying a clockwise arc results in a counterclockwise arc after the transformation is applied. If the path ends with an unclosed subpath, this method adds a line connecting the current point to the starting point of the arc. If there is no unclosed subpath, this method creates a new subpath whose starting point is the starting point of the arc. The ending point of the arc becomes the new current point of the path.

## See Also

### Drawing a path

- [move(to:)](swiftui/path/move(to:).md)
- [addArc(center:radius:startAngle:endAngle:clockwise:transform:)](swiftui/path/addarc(center:radius:startangle:endangle:clockwise:transform:).md)
- [addArc(tangent1End:tangent2End:radius:transform:)](swiftui/path/addarc(tangent1end:tangent2end:radius:transform:).md)
- [addCurve(to:control1:control2:)](swiftui/path/addcurve(to:control1:control2:).md)
- [addEllipse(in:transform:)](swiftui/path/addellipse(in:transform:).md)
- [addLine(to:)](swiftui/path/addline(to:).md)
- [addLines(_:)](swiftui/path/addlines(_:).md)
- [addPath(_:transform:)](swiftui/path/addpath(_:transform:).md)
- [addQuadCurve(to:control:)](swiftui/path/addquadcurve(to:control:).md)
- [addRect(_:transform:)](swiftui/path/addrect(_:transform:).md)
- [addRects(_:transform:)](swiftui/path/addrects(_:transform:).md)
- [addRoundedRect(in:cornerSize:style:transform:)](swiftui/path/addroundedrect(in:cornersize:style:transform:).md)
- [closeSubpath()](swiftui/path/closesubpath().md)