diff --git a/poly2d/p2d_attrib.c b/poly2d/p2d_attrib.c
index 1e7fc7b..5158e78 100644
--- a/poly2d/p2d_attrib.c
+++ b/poly2d/p2d_attrib.c
@@ -29,17 +29,17 @@ static double angle_3(const struct v2d *a, const struct v2d *b,
 	double aa, bb;
 	double angle;
 
-	ax = b->x-a->x;
-	ay = b->y-a->y;
-	bx = c->x-b->x;
-	by = c->y-b->y;
+	ax = b->x - a->x;
+	ay = b->y - a->y;
+	bx = c->x - b->x;
+	by = c->y - b->y;
 
 	aa = hypot(ax, ay);
 	bb = hypot(bx, by);
 
-	angle = acos((ax*bx+ay*by)/aa/bb)/M_PI*180.0;
+	angle = acos((ax * bx + ay * by) / aa / bb) / M_PI * 180.0;
 
-	return (ax*by-ay*bx) >= 0 ? angle : -angle;
+	return ax * by - ay * bx >= 0 ? angle : -angle;
 }
 
 /*