Issue 7061: Explained 'gon'
diff --git a/Lib/turtle.py b/Lib/turtle.py
index 18d9a56..5e55f09 100644
--- a/Lib/turtle.py
+++ b/Lib/turtle.py
@@ -1575,7 +1575,10 @@
         >>> turtle.left(90)
         >>> turtle.heading()
         90
-        >>> turtle.degrees(400.0)  # angle measurement in gon
+
+        Change angle measurement unit to grad (also known as gon,
+        grade, or gradian and equals 1/100-th of the right angle.)
+        >>> turtle.degrees(400.0)
         >>> turtle.heading()
         100