I learned how to do circle, I tested to see if the starting point is the center of a circle or one of the point on the circle, and I learend the starting point is a part of the circle, not the center of the circle I am trying to draw. Penup and pendown steps need to added after my first attempt. It was fun.

This was much easier than K, but a bit harder than L. I was glad that I learned how to do circle, my font is not so pretty, maybe my letter O is too round since I used a perfect circle, but this is what I can do without thinking too much. So, I was just happy that I complete this task.

typeface.py

@@ -83,7 +83,7 @@ def draw_letter_l(unit):
     left(90)
     forward(8*unit)
     left(90)
-    
+
 
 def draw_letter_m(unit):
     pass
@@ -92,7 +92,23 @@ def draw_letter_n(unit):
     pass
 
 def draw_letter_o(unit):
-    pass
+    penup()
+    forward(4*unit)
+    pendown()
+    circle(4*unit)
+    penup()
+    left(90)
+    forward(2*unit)
+    right(90)
+    pendown()
+    circle(2*unit)
+    penup()
+    backward(4*unit)
+    right(90)
+    forward(2*unit)
+    pendown()
+    left(90)
+
 
 def draw_letter_p(unit):
     pass