function triangle(indx, radius) {
let stepsize = (indx * Math.PI) / 3;
let startangle = Math.PI / 6 + stepsize;
let stopangle = Math.PI / 6 + Math.PI / 3 + stepsize;
return Plot.area([0, 0], {
x1: [0, 0],
y1: [0, 0],
x2: [radius * Math.cos(startangle), radius * Math.cos(stopangle)],
y2: [radius * Math.sin(startangle), radius * Math.sin(stopangle)],
fill: "grey",
fillOpacity: 0.5,
stroke: indx % 2 == 0 ? "black" : "",
mixBlendMode: "color-burn"
});
}