public static void setHeight(int height) {
        h = height;	// h = basic dimension: height (distance between two adj centresr aka size)
        r = h / 2;	// r = radius of inscribed circle
        s = (int) (h / 1.73205);	// s = (h/2)/cos(30)= (h/2) / (sqrt(3)/2) = h / sqrt(3)
        t = (int) (r / 1.73205);	// t = (h/2) tan30 = (h/2) 1/sqrt(3) = h / (2 sqrt(3)) = r / sqrt(3)
    }