invoke the perimeter function which is supposed to return the sum of 4 lines with vertices

(point A-B,point B-C, point C-D, point D-A)

Point a, b, c, d;

public Quadilateral(Point a, Point b, Point c, Point d) {

this.a = a;

this.b = b;

this.c = c;

this.d = d;

}

public double getPerimeter() {

fill in the code here

}

invoke area function as well

area of triangle ABD + area of triangle BCD