Simple Logo Commands
To begin drawing or to clear the screen:
DRAW or CS (CLEARSCREEN) - one of these commands (depending
on your version of Logo) should clear the screen and put the turtle in
the center, facing up
Basic Logo commands for turtle movement:
FD (FORWARD) - moves the turtle in the direction of its "nose",
requires a number of steps
Example: FD 50 moves the turtle forward 50 "turtle steps"
BK (BACK) - moves the turtle in the opposite direction from its
"nose", requires a number of steps
Example: BK 75 moves the turtle backwards 75 "turtle steps"
RT (RIGHT) - turns the turtle to the right, but does not move
it forward, requires a number of degrees
Example: RT 90 turns the turtle right 90 degrees
LT (LEFT) - turns the turtle to the left, but does not move it
forward, requires a number of degrees
Example: LT 30 turns the turtle left 30 degrees
Pen control (the turtle has a drawing "pen"):
PU (PENUP) - after this command, turtle movement will not draw a
line
Example: PU
PD (PENDOWN) - after this command, turtle movement will draw
a line
Example: PD
PPT (PENPAINT) - in some versions of Logo, this is equivalent
to PD, may be PP in some version of Logo
Example: PPT
PE (PENERASE) - after this command, turtle movement will erase
whatever it crosses over
Example: PE
Shortcut to repetition of multiple commands:
REPEAT - allows a single set of commands to be repeated, requires
a number of repetitions and a set of commands in square brackets ([ ])
Example: REPEAT 2 [FD 25 RT 60] is equivalent to FD 25 RT 60
FD 25 RT 60
Example: REPEAT 3 [FD 50 RT 120] is equivalent to FD 50 RT 120
FD 50 RT 120 FD 50 RT 120
Try this!
Try to determine what Logo commands would be required to make these shapes.
Imagine that you are the turtle (shown as a triangle on the pictures below)
walking aound the shape. The numbers give the size in "turtle steps." Write
down the movements you make in "Logo language." When you are done, click
on the shape to see one or two possible answers.
