Movement of turtle and working with canvas
Command Alternative Description of command Example
forward <x> fd <x> Move the turtle forward on x points. forward 10
back <x> bk <x> Move the turtle back on x points. back 10
left <a> lt <a> turtle rotation by a degrees to the left. left 90
right <a> rt <a> turtle rotation by a degrees to the right. right 90
penup pu Lifting turtle. Turtle stops drawing the line. penup
pendown pd Laying turtle. The turtle will draw a line. pendown
showturtle st Viewing turtle. Turtle will be visible. showturtle
hideturtle ht Hiding turtle. Turtle will be invisible. hideturtle
home   Turtle will stand to the middle of the screen (in its default position). home
clean   Erases the entire canvas. clean
clearscreen cs Performs command home and clean. clearscreen



Mathematical operations and functions
Expression Description of expression Example
( <x> ) Brackets. It is recommended to add all the missing brackets in mathematical expressions. (10 + ((sin 5) ^ 3))
<x> + <y> Total numbers x a y. 10 + 5
<x> - <y> Difference of numbers x a y. 10 - 5
<x> * <y> The product numbers x a y. 10 * 5
<x> / <y> Share numbers x a y. 10 / 5
<x> ^ <y> Power, xy. 10 ^ 2
sqrt <x> Square root of number x. sqrt 100
sin <x> Trigonometric sine function. Number x is the angle in degrees. sin 45
cos <x> Trigonometric functions cosine. Number x is the angle in degrees. cos 45
tan <x> Trigonometric functions tangent. Number x is the angle in degrees. tan 45
arcsin <x> Inverse trigonometric function sine. x is the number and the result is returned in degrees. arcsin 1
arccos <x> Inverse trigonometric function cosine. x is the number and the result is returned in degrees. arccos 1
arctan <x> Inverse trigonometric function tangent. x is the number and the result is returned in degrees. arctan 1



Control structures
Command Description of expression Example
repeat <K> [ <commands> ] Turtle repeated block to the <K>-times.
repeat 4 [
  left 90
  fd 50
]
if <C> [ <commands> ] Simple branching. If the turtle evaluate <C> be true, then executes the next block of commands.
if 1 < 4 [
  left 90
  fd 50
]
ifelse <C> [ <commands1> ] [ <commands2> ] Branching with else. If the turtle evaluate <C> be true, then makes a block of commands1, otherwise the block of commands2.
if 1 > 4 [
  left 90
  fd 50
] [
  right 90
  fd 50
]
to <name> <parameters> <commands> end Function definition name. The parameters of function are variables beginning with a colon and are separated by a space. The function body follows.
to triangle :side
  repeat 3 [
   right 120
   fd :side
  ]
end