constructor([stroke], [background], [opacity], [x], [y], [width], [height])

Creates an instance of Arc shape.

Name	Type	Default	Description
`[stroke]`	Stroke		A border of the shape.
`[background]`	string		Color, gradient, or image background, similar to CSS. Use an empty string to remove the background.
`[opacity]`	number	1	Opacity of the shape (0 to 1).
`[x]`	number	0	Horizontal position from the left edge.
`[y]`	number	0	Vertical position from the top edge.
`[width]`	number	100	Width of the ellipse (horizontal diameter).
`[height]`	number		Height of the ellipse (vertical diameter). If omitted, height will be same as width.