Circle Block
You simply need to give width, height and these values will define diameters of circle block.
new CircleBlock({width: 120, height: 60, backgroundColor: "black"})
Custom Radius
For creating something like elipse shape you can define different diameters with width and height on circle block.
new CircleBlock({...options, width: 50, height: 120})
Angles
You can define start and end point of circle block angle with startAngle and endAngle options.
new CircleBlock({...options, startAgnle: 0, endAngle: Math.PI})
Inner Radius
Inner radius can create pie like shapes with startAngle and endAngle options in circle block.
new CircleBlock({...options, startAgnle: 0, endAngle: Math.PI, innerRadius: 15})
Border
As in the rectangle block example circles also support border option.
new CircleBlock({...options, border: "30px solid white"})