var x = [0,1,0,6],
y = [2,0,1,6],
n = x.length;
var sqrt = Math.sqrt,
pow = Math.pow;
var A, An = n - 2, AB,
B, Bn = n - 1, BC,
C, Cn = n - 0, CA,
P, Pn = [],
S, Sn = [];
for (A = 0; A < An; A++) {
for (B = A + 1; B < Bn; B++) {
for (C = B + 1; C < Cn; C++) {
if ((x[A] - x[C]) *
(y[B] - y[C]) ==
(x[B] - x[C]) *
(y[A] - y[C])) continue;
AB = sqrt(pow(x[A] - x[B], 2)
+ pow(y[A] - y[B], 2));
BC = sqrt(pow(x[B] - x[C], 2)
+ pow(y[B] - y[C], 2));
CA = sqrt(pow(x[C] - x[A], 2)
+ pow(y[C] - y[A], 2));
P = AB + BC + CA;
Pn.push(P); P /= 2;
S = sqrt(P * (P - AB) * (P - BC) * (P - CA));
Sn.push(S);
}
}
}
console.table({P: Pn, S: Sn});