Basic Graphics #3 - Angle

Using  -  The Python Computer Language

                Turtle Graphics Library

3.   ANGLE

ROTATION RIGHT

 

 

SAVE AS

 

>>> import turtle

>>>

>>> Pt = turtle.Turtle()

>>>

>>> Pt.right(45)

>>>

>>> turtle.done()

>>> 

 

SAVE

 

 

Pt.right(number of degrees)

    Arrow head turns around to its right     

    side   

 

The arrow head spins at its position,

    which is the pixel at its front point

ROTATION LEFT

 

SAVE AS

 

>>> import turtle

>>>

>>> Pt = turtle.Turtle()

>>>

>>> Pt.left(45)

>>>

>>> turtle.done()

>>> 

 

SAVE

 

 

Pt.left(number of degrees)

    Arrow head turns around to its left side

     

The arrow head spins at its position, 

    which is the pixel at its front point

ROTATED LINE

 

 

SAVE AS

 

>>> import turtle

>>>

>>> Pt = turtle.Turtle()

>>>

>>> Pt.right(120)

>>> Pt.forward(200)

>>>

>>> turtle.done()

>>> 

 

SAVE

 

Pt.right(number of degrees)

Pt.forward(number of pixels)

            x 1

ANGLE

 

 

SAVE AS

 

>>> import turtle

>>>

>>> Pt = turtle.Turtle()

>>>

>>> Pt.right(120)

>>> Pt.forward(200)

>>> Pt.right(120)

>>> Pt.forward(200)

>>>

>>> turtle.done()

>>> 

 

SAVE

 

Pt.right(number of degrees)

Pt.forward(number of pixels)

            x 2

TRIANGLE

 

SAVE AS

 

>>> import turtle

>>>

>>> Pt = turtle.Turtle()

>>>

>>> Pt.right(120)

>>> Pt.forward(200)

>>> Pt.right(120)

>>> Pt.forward(200)

>>> Pt.right(120)

>>> Pt.forward(200)

>>>

>>> turtle.done()

>>>

 

SAVE

Pt.right(number of degrees)

Pt.forward(number of pixels)

            x 3

USING THE OUTSIDE ANGLE

Pt.forward(number of pixels)

Pt.right(number of degrees)

    the line proceeds in the direction,

      - of, number of degrees, right,

      - from, the previous direction

         of the arrow

THE LOOP

 

 

When there is a repetition of

a sequence of actions,

instead of writing out the sequence,

a number of times,

it is easier to write it as a loop.

 

So,

 

Pt.right(120)

Pt.forward(200)

Pt.right(120)

Pt.forward(200)

 

Can be written, as the “for” loop  -

 

for i in range(2):

    Pt.right(120)

    Pt.forward(200)

 

i   means “integer”, “whole number”

  

Also,

 

Pt.right(120)

Pt.forward(200)

Pt.right(120)

Pt.forward(200)

Pt.right(120)

Pt.forward(200)

 

Can be written, as the “for” loop  -

 

for i in range(3):

    Pt.right(120)

    Pt.forward(200)

 

for i in range(number of times):

     sequence of actions

    number of times,

    is the number of times to do (loop)

    this sequence of actions 

(c) Katherine Stuart 2020

Dochas Books Film