SOURCE

const getPiePosition = (indx, total) => {
    var p = {
        radius: '',
        center: ['', '']
    };

    if (total === 1) {
        p.radius = '75%';
        p.center = ['50%', '50%'];
    }
    else if (total === 2) {
        p.radius = '50%';
        if (indx === 0) {
            p.center = ['25%', '50%'];
        }
        else {
            p.center = ['75%', '50%'];
        }
    }
    else if (total === 3) {
        p.radius = '45%';
        if (indx === 0) {
            p.center = ['25%', '33%'];
        }
        else if (indx === 1) {
            p.center = ['75%', '33%'];
        }
        else {
            p.center = ['50%', '75%'];
        }
    }
    else if (total === 4) {
        var inx = indx % 2;
        var ix = Math.floor(indx / 2);
        p.radius = '40%';
        p.center[0] = inx === 0 ? '25%' : '75%';
        p.center[1] = ix === 0 ? '30%' : '75%';
    }
    else {
        var inx = indx % 3;
        var ix = Math.floor((indx + 1) / 3);
        p.radius = '35%';
        if (ix === 0) {
            p.center[1] = '25%';
        }
        else {
            p.center[1] = '75%';
        }
        if (inx === 0) {
            p.center[0] = '25%';
        }
        else if (inx === 1) {
            p.center[0] = '75%';
        }
        else {
            p.center = ['50%', '50%'];
        }
    }
    return p;
}

var d = getPiePosition(4, 5);
console.log(d)