public class Shape {
	
	private double[][] points;
	
	public Shape(int numPoints) {
		this.points = new double[numPoints][3];
	}
	
	public void setPoint(int i, Point point) {
		points[i][0] = point.x;
		points[i][1] = point.y;
		points[i][2] = point.z;
	}
	
	public Point getCentreOfMass() {
		double xSum = 0.0;
		double ySum = 0.0;
		double zSum = 0.0;
		
		for (int i = 0; i < points.length; ++i) {
			xSum += points[i][0];
			ySum += points[i][1];
			zSum += points[i][2];
		}
		
		return new Point((xSum / points.length), (ySum / points.length), (zSum / points.length));
	}
	
}