update a,b,c,i

I was struggled with the error of test.py for a while, then I copied code to ChatGPT and asked it,
I tried pip install superturtle to solve the problem under AI's help, which makes me relieved.

Letter I: the easiest one

Letter A: I started by using angle 80, then I figired that it's hard to do the math, so I changed it to 60 for easier caculation

Letter B: I spent some time exploring how circle works and how initial direction might influence the circle draw, i also use speed() to fasten the process

Letter C: two quater circle combined

To make the pen get the initial position, I tried position() and home(), but they didn't work very well. Then I asked ChatGPT how to make it home to make proof.py work
it gives me specific steps using penup and pendown etc to make it back, which is complicated. So I asked if there is a easier way to achieve this. Then it provides me with initial_position code, which concise the process.

typeface.py

@@ -1,5 +1,5 @@
 # typeface.py
-# By Chris Proctor and _________
+# By Chris Proctor and _____Grace____
 
 # Contains one function for each letter in the English alphabet. 
 # Each function should draw its letter at a scale of `unit`, and then 
@@ -13,14 +13,60 @@ from turtle import *
 from math import sqrt
 
 def draw_letter_a(unit):
-    pass
+    initial_position = pos()
+    initial_heading = heading()
+    left(60)
+    forward(8 * unit)
+
+    right(120)
+    forward(8 * unit)
+
+    backward(4 * unit)
+    right(120)
+    forward(4 * unit)
+    
+    penup()
+    setpos(initial_position)  # Return to original position
+    setheading(initial_heading)  # Return to original heading
+    pendown()
 
 def draw_letter_b(unit):
-    pass
+    initial_position = pos()
+    initial_heading = heading() 
+    speed(0)
+    circle(2 * unit, 180)
+    left(180)
+    circle(2 * unit, 180)
+    left(90)
+    forward(8 * unit)
+
+    penup()
+    setpos(initial_position)  # Return to original position
+    setheading(initial_heading)  # Return to original heading
+    pendown()
 
 def draw_letter_c(unit):
-    pass
+    initial_position = pos()
+    initial_heading = heading()
+    speed(0)
+    penup()
+    forward(4 * unit)
+    left(90)
+    forward(8 * unit)
+    pendown()
+    left(90)
+    circle(4 * unit, 180)
 
+    penup()
+    right(90)
+    forward(2 * unit)
+    pendown()
+
+    penup()
+    setpos(initial_position) 
+    setheading(initial_heading) 
+    pendown()
+    
 def draw_letter_d(unit):
     pass
 
@@ -37,7 +83,23 @@ def draw_letter_h(unit):
     pass
 
 def draw_letter_i(unit):
-    pass
+    initial_position = pos()
+    initial_heading = heading() 
+    penup()
+    forward(4 * unit)
+    left(90)
+    pendown()
+    forward(5 * unit)
+    penup()
+    forward(1 * unit)
+    pendown()
+    forward(1 * unit)
+
+    penup()
+    setpos(initial_position)  
+    setheading(initial_heading)  
+    pendown()
+
 
 def draw_letter_j(unit):
     pass