If you get stuck on a problem, leave it blank and return to it later. You will receive partial credit for code with minor errors, but please check your work if you have time.

1. Write a procedure that accepts a number as input and then draws a hexagon whose side length equals that number.

   Hint: We did this with squares and triangles at the beginning of the semester.

   Solution:

   to hexagon :input
    repeat 6 [forward :input right 60
   end
   

2. Write a procedure that asks a person for their favorite musician and then uses the musican's last name in a sentence, as shown below. Punctuation counts!

   Who is your favorite musician?
   K. D. Lang
   Everybody loves Lang!
   ? musicianchat
   Who is your favorite musician?
   Prince
   Everybody loves Prince!
   ? musicianchat
   Who is your favorite musician?
   John Lennon
   Everybody loves Lennon!
   

   Hint: There were some procedures like this in Chapter 1.

   Solution:

   to musicianchat
    print [Who is your favorite musician?]
    print sentence [Everybody loves] word last readlist "!
   end
   

3. Professor Burgiel wanted to draw a picture of a smiley face (below left).  
   When she ran her program, what she got was the picture above on the right. Find as many errors in the following two procedures as you can:

   to square :size
    repeat 4 [forward 40 right 90]
   end
   
   to face
    right 180 repeat 180 [forward 1 right 1] ; mouth
    penup forward 50 pendown square 40       ; right eye 
    penup right 90 forward 80 square 40      ; left eye
    penup left 90 forward 10 left 90 forward 20 pendown
    square 20                                ; nose
   end
   

   Hint: Go through the procedure step by step, drawing what the turtle draws at each step.

   Solution:

   to face
    right 180 repeat 180 [forward 1 right 1] ; mouth
    penup forward 50 pendown square 40       ; right eye 
    penup right 90 forward 80 left 90 pendown square 40      ; left eye
    penup left 90 forward 10 left 90 forward 20 pendown
    square 20                                ; nose
   end
   
   to square :size
    repeat 4 [forward :size right 90]
   end
   

4. Write a Logo operation that takes one input and outputs "false if the input is a list and "true otherwise.

   Hint: See Chapter 4.

   Solution:

   to notalistp :input
    output not listp :input
   end
   

5. Write a recursive procedure to keep asking the same question until the user gets the right answer.

   ? keepquizzing
   Who is the greatest musician of all time?
   K. D. Lang
   Who is the greatest musician of all time?
   Michael Jackson
   Who is the greatest musician of all time?
   Billy Joel
   Who is the greatest musician of all time?
   John Lennon
   Good job!
   ?
   

   Hint: This is similar to the maze program we worked on in class.

   Solution:

   to keepquizzing
    print [Who is the greatest musician of all time?]
    if equalp [John Lennon] readlist [print [Good job!] stop]
    keepquizzing
   end
   

2
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8
16
32
64

Hint: The students probably do not know how to raise a number to a power in Logo; that's why this is an extra credit problem. They will receive partial credit if they make a reasonable guess at how to exponentiate and get everything else right.

Solution:

for [i 1 6] [print power 2 :i]