function A=ar1(c1_x,c1_y, cj_x,cj_y, c2_x,c2_y, d,G1_y,W_y)
%	global G1_y W_y
	bis = 0.5 * (angle(cj_x,cj_y, c1_x,c1_y) + angle(c2_x,c2_y, cj_x,cj_y));
	cf = abs(cos(bis - pi/2.0));
	gc = cj_y - G1_y;
	gw = W_y - G1_y;
	A = 2.2 * (gc/gw) + 2.0;
	A = A * cf * d * pi/2.0;