Как найти координаты третьей вершины треугольника, зная все стороны и две вершины?

function calcDistance(firstPos, secondPos) {
    if (secondPos.x && secondPos.y && firstPos.x && firstPos.y) {
        var distance = Math.sqrt((secondPos.x - firstPos.x) ** 2 + (secondPos.y - firstPos.y) ** 2);
        return distance
    } else {
        return 'error!!!!!!!'
    }
}
 
 
function calcMiddle (firstPoint, secondPoint, target) {
    // a = (r0^2 - r1^2 + d^2 ) / (2d)
    // h^2 = r0^2 - a^2
    // P2 = P0 + a ( P1 - P0 ) / d
    //"p0" is first receiver
    //"p1" is second receiver
    // "r0" is distance to target from p0
    // "r1" is distance to target from p1
    // "a" - distance to the point of intersection between two circles  as will be named "p2"
    // "d" - distance between two receivers
    // "h" - distance between two receivers p2 point
    r0 = calcDistance(firstPoint, target);
    r1 = calcDistance(secondPoint, target);
    d = calcDistance(firstPoint, secondPoint);
    a = (r0**2-r1**2+d**2)/(2*d);
    h = r0**2 - a**2;
    p2x = firstPoint.x+a*(secondPoint.x-firstPoint.x)/d;
    p2y = firstPoint.y+a*(secondPoint.y-firstPoint.y)/d;
    //x3 = x2 +- h ( y1 - y0 ) / d
    // y3 = y2 -+ h ( x1 - x0 ) / d
    p3x1 = p2x-Math.sqrt(h)*(secondPoint.y-firstPoint.y)/d;
    p3y1 = p2y+Math.sqrt(h)*(secondPoint.x-firstPoint.x)/d;
    p3x2 = p2x+Math.sqrt(h)*(secondPoint.y-firstPoint.y)/d;
    p3y2 = p2y-Math.sqrt(h)*(secondPoint.x-firstPoint.x)/d;
    console.log(r0, "- is distance to target from p0" );
    console.log(r1, "- is distance to target from p1");
    console.log(d, "- distance between two receivers");
    console.log(a, "- distance to the point of intersection between two circles");
    console.log(Math.sqrt(h), "- distance between two receivers 'p2' point");
    console.log("Координаты передатчика вычислена: ", p3x1, p3y1);
    console.log("Координаты передатчика вычислена: ", p3x2, p3y2);
    console.log("Координаты передатчика на самом деле: ", target.x, target.y);
 
}