Find centroid of a triangle with JavaScript

triangle-center.js

// Very simple way to compute the center (centroid) of a triangle.
// The only things you have to know are the three vectors forming the triangle.

// vector = [x, y, z];
var vectorA = [-1, -3, -2];
var vectorB = [2, 1, 2];
var vectorC = [8, -4, 1];

var centerX = ((vectorA[0] + vectorB[0] + vectorC[0]) / 3);
var centerY = ((vectorA[1] + vectorB[1] + vectorC[1]) / 3);
var centerZ = ((vectorA[2] + vectorB[2] + vectorC[2]) / 3);

var center = [centerX, centerY, centerZ];

2D function:

function getTriangleCentroid(arr){
	var centerX = (arr[0].x + arr[1].x + arr[2].x) / 3;
	var centerY = (arr[0].y + arr[1].y + arr[2].y) / 3;
	return createVector(centerX, centerY);
}

Usage:

console.log(getTriangleCentroid([{x: -1, y: 2}, {x: -3, y: 1}, {x: -2, y: 2}]));