diff --git a/readme.md b/readme.md
index 055fd5d..486a39e 100644
--- a/readme.md
+++ b/readme.md
@@ -5736,7 +5736,8 @@ Cylinder with a rounded end.
 ---
 <a name="Rounded_polygon"></a>
 ## Rounded_polygon
-Draw a polygon with rounded corners. Each element of the vector is the XY coordinate and a radius. Radius can be negative for a concave corner.
+Draw a polygon with rounded corners. Each element of the vector is the XY coordinate and a radius in clockwise order.
+Radius can be negative for a concave corner.
 
 Because the tangents need to be calculated to find the length these can be calculated separately and re-used when drawing to save calculating them twice.
 
@@ -5747,6 +5748,7 @@ Because the tangents need to be calculated to find the length these can be calcu
 ### Functions
 | Function | Description |
 |:--- |:--- |
+| `circle_tangent(p1, p2)` | Compute the clockwise tangent between two circles represented as [x,y,r] |
 | `rounded_polygon_length(points, tangents)` | Calculate the length given the point list and the list of tangents computed by ` rounded_polygon_tangents` |
 | `rounded_polygon_tangents(points)` | Compute the straight sections needed to draw and to compute the lengths |
 
diff --git a/utils/rounded_polygon.scad b/utils/rounded_polygon.scad
index 8b4db06..85d0f6b 100644
--- a/utils/rounded_polygon.scad
+++ b/utils/rounded_polygon.scad
@@ -18,13 +18,14 @@
 //
 
 //
-//! Draw a polygon with rounded corners. Each element of the vector is the XY coordinate and a radius. Radius can be negative for a concave corner.
+//! Draw a polygon with rounded corners. Each element of the vector is the XY coordinate and a radius in clockwise order.
+//! Radius can be negative for a concave corner.
 //!
 //! Because the tangents need to be calculated to find the length these can be calculated separately and re-used when drawing to save calculating them twice.
 //
 include <../utils/core/core.scad>
 
-function circle_tangent(p1, p2) =
+function circle_tangent(p1, p2) = //! Compute the clockwise tangent between two circles represented as [x,y,r]
     let(
         r1 = p1[2],
         r2 = p2[2],
@@ -32,11 +33,8 @@ function circle_tangent(p1, p2) =
         dy = p2.y - p1.y,
         d = sqrt(dx * dx + dy * dy),
         theta = atan2(dy, dx) + acos((r1 - r2) / d),
-        xa = p1.x +(cos(theta) * r1),
-        ya = p1.y +(sin(theta) * r1),
-        xb = p2.x +(cos(theta) * r2),
-        yb = p2.y +(sin(theta) * r2)
-    )[ [xa, ya], [xb, yb] ];
+        v = [cos(theta), sin(theta)]
+    )[ p1 + r1 * v, p2 + r2 * v ];
 
 function rounded_polygon_tangents(points) = //! Compute the straight sections needed to draw and to compute the lengths
     let(len = len(points))