This document defines and provides examples of common Logo primitives including fd, bk, rt, lt, pd, pu, setc, setpensize, and seth. It explains that primitives are built-in commands that tell the Logo application what to do. Each primitive is defined, its syntax is provided, and examples of its use are given.

1. Logo Primitives

2. Primitives
• Built in words in Microworlds Logo
that tell the application what to do.
• Example: fd, bk, show, pos

3. fd (forward)
• Definition: Moves the turtle forward.
– Syntax: fd number
• Example: fd 20
• Notes:
– The turtle leaves a trace if its pen is down
– The maximum number is 9999

4. bk (back)
• Definition: Moves the turtle backwards
– Syntax: bk number
• Example: bk 50
• Notes:
– The turtle leaves a trace if its pen is down
– The maximum number is 9999

5. rt (right)
• Definition: Turns the turtle to the
right
– Syntax: rt number
• Example: rt 90
• Notes:
– The maximum number is 9999

6. lt (left)
• Definition: Turns the turtle to the
left.
– Syntax: lt number
• Example: lt 90
• Notes:
– The maximum number is 9999

7. Degrees

8. pd (pen down)
• Definition: Puts down the pen of the
current turtle. The turtle will then
leave a trace when it moves.
• Example: pd
• Notes: It does not leave a trace if it
is dragged.

9. pu (pen up)
• Definition: Lifts the pen of the
current turtle. The turtle will not
leave a trace when it moves.
• Example: pu

10. setc (set pen color)
• Definition: Sets the color of the turtle’s
pen.
– Syntax: setc name or number
• Example: setc “red
setc 16
• Notes:
– If the turtle has its original shape it will show the color
– If using a name input you must use a “ before the name.

11. setpensize
• Definition: Sets the pen size of the
turtle
– Syntax: setpensize number
• Example: setpensize 20
• Notes:
– The original pen size is 1.
– The maximum pen size is 100.

12. seth (set heading)
• Definition: Sets the turtle’s heading
to the specified direction (in
degrees)
–