Issue 7061: Explained 'gon'

Doc/library/turtle.rst

@@ -714,7 +714,10 @@ Settings for measurement
       >>> turtle.left(90)
       >>> turtle.heading()
       90.0
-      >>> 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()
       100.0
       >>> turtle.degrees(360)
@@ -1511,6 +1514,7 @@ Window control
    :param args: a color string or three numbers in the range 0..colormode or a
                 3-tuple of such numbers
 
+
    Set or return background color of the TurtleScreen.
 
    .. doctest::

Lib/turtle.py

@@ -1575,7 +1575,10 @@ class TNavigator(object):
         >>> 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