**Commands [and their abreviations]**

**forward** 100 [fd 100]

Moves the turtle 100 pixels at the current heading.

**back** 100 [bk 100]

Moves the turtle back 100 pixels at the current heading.

**right** 30 [rt 30]

Rotates the turtle clockwise through a 30 degree angle.

**left** 30 [lt 30]

Rotates the turtle counterclockwise through a 30 degree angle.

**setHeading** 45 [seth 45]

Directs the turtle to an angle of 45 degrees. (All angles are measured in the usual Cartesian manner, that is counterclockwise from 3 O'clock.)

**setX** 30

Moves the turtle horizontally to the coordinate x = 30.

**setY** 40

Moves the turtle vertically to the coordinate y = 40.

**setXY** 30,40

Moves the turtle to the coordinates 30,40.

**incXY** 3,4

Increases the x coordinate of the turtle by 3 and the y coordinate by 4.

**Functions**

**xcor** ( )

Returns the turtle’s x coordinate.

**ycor** ( )

Returns the turtle’s y coordinate.

**xyCor** ( )

Returns a list of the turtle’s x and y coordinates.

**heading** ( )

Returns the turtle's heading.

**direction** (30,40) or toward(30,40)

Returns the direction of the point 30,40 from the current location of the turtle. It does not rotate the turtle.

**distance** (30,40)

Returns the distance from the current location of the turtle to the point 30,40.

**clickPoint** ( )

Returns the x and y coordinates of the point of the mouse click--useful in importing data into a program.

**Intersection**(ax,ay,bx,by)

Returns the intersection of two lines whose endpoints are ax, ay and bx, by.

**Miscellaneous**

**StartTurtle** [st] tName

Initiates the turtle (control) with the name tName, giving the control the custom properties of x, y coordinates, heading, pen state (up or down) and graphic points. The associated graphic (trace)is {tName} &"grc"

**Tell** tName

Tell the turtle who he is talking to.

**home**

Moves the turtle to the origin and pointing to the right.

**setHome** 30,40

Sets the home position of the turtle a distance 30 to the right of screen-center, and a distance 40 above screen-center. (It does not move the turtle home.)

**cleanG** tName

Clears the graphic points but not the graphic. If tName is omitted, it clears all graphic points.

**penUp** [pu]

Raises the drawing pen. The turtle will no longer leave a track as he moves.

**penDown** [pd]

Lowers the drawing pen.

**TurtlePtToMousePt**

Converts turtle coordinates, measured from the screen's center, to mouse coordinates, measured from the upper left.

**MousePtToTurtlePt**

See above.

**centeredCircle** 5

Draws a circle, centered about the current turtle position, of radius 5.

**Label** "x"

Prints an “x” (or whatever you place within quotes) at the current turtle location.

**sci** (num,sig)

Returns the input num in scientific notation with "sig" significant figures, e.g. sci(312345.67, 3) becomes 3.12*10^5.

**commaFormat**(num)

Returns the num with commas delimiting each triplet, i.e. commaFormat(9999999) returns 9,999,999.

**SetColor** red

Sets the forecolor of the active turtle to red. Must follow Tell.

**SetSize** 3

Sets the linesize of the active turtle to 3

**SetArrow** true

Sets the end arrow of the active turtle to true.