This document introduces Python turtle graphics and related math concepts. It discusses functions like forward(), left(), right(), and circle() to move and draw with the turtle. It covers angles, variables, shapes, and conditional statements. Examples show how to use these functions and concepts to draw squares, circles of different radiuses, and respond to user input with the turtle. The goal is to learn Python turtle graphics through interactive examples and exercises.

1. INTRODUCTION TO
MATH WITH PYTHON TURTLE
PHSTech Club
Portola High School
1001 Cadence
Irvine, CA 92618
NR Computer Learning Center
1835 W. Orangewood, Suite 200
Orange, CA 92868
(714) 505-3475
www.nrclc.com

2. OBJECTIVE
 Angle
 Circle
 Variable

3. PYTHON
An easy-to-learn programming language
Code is quite easy to read
Python has features that allow you to put together
simple animations for creating your own games.
https://trinket.io/python

4. PYTHONTURTLE FUNCTION FORWARD()
 Forward(distance) - Move the turtle forward by the specified distance, in the
direction the turtle is headed.
 Example
t.forward(100) # move 100 steps forward

5. ANGLE

6. ANGLE
Angles are a measure of turn and are measured in degrees.
Right Angle – Equal to 90o
StraightAngle – equal to 180o
Straight line – equal to 360o

7. PYTHONTURTLE FUNCTION LEFT() &
RIGHT()
 Left(angle) -Turn turtle left by angle units.
 Right(angle) -Turn turtle right by angle units.
 Example
t.forward(100) # move 100 steps forward
t.left(90) # turn 90 degrees to the left
t.forward(100) # move 100 steps forward
t.right(90) # turn 90 degrees to the right
t.forward(100) # move 100 steps forward

8. EXERCISE 1: USING 900 ANGLE
import turtle
t = turtle.Turtle()
t.forward(100)
t.left(90)
t.forward(100)
t.left(90)
t.forward(100)
t.left(90)
t.forward(100)
t.left(90)

9. EXERCISE 2: USING 650 ANGLE
import turtle
t = turtle.Turtle()
t.forward(50)
t.left(60)
t.forward(50)
t.left(60)
t.forward(50)
t.left(60)
t.forward(50)
t.left(60)
t.forward(50)
t.left(60)
t.forward(50)
t.left(60)

10. EXERCISE3: USING 450 ANGLE
import turtle
t = turtle.Turtle()
t.forward(50)
t.left(45)
t.forward(50)
t.left(45)
t.forward(50)
t.left(45)
t.forward(50)
t.left(45)
t.forward(50)
t.left(45)
t.forward(50)
t.left(45)
t.forward(50)
t.left(45)
t.forward(50)
t.left(45)

11. CIRCLE

12. PYTHON FUNCTION: CIRCLE()
turtle.circle(radius, extent, steps)
 radius - Draw a circle with given radius.The center is radius units left of the turtle;
 extent (optional)– an angle – determines which part of the circle is drawn. If
extent is not given, draw the entire circle. If extent is not a full circle, one endpoint
of the arc is the current pen position. Draw the arc in counterclockwise direction if
radius is positive, otherwise in clockwise direction. Finally the direction of the
turtle is changed by the amount of extent.
 Steps (optional)- determines the number of steps to use.
 Example
 turtle.circle(50) # draw full circle
 turtle.circle(120, 180) # draw a semicircle

13. EXERCISE 4: USINGVARIABLE
import turtle
t = turtle.Turtle()
t.circle(5)
t.circle(10)
t.circle(15)
t.circle(20)
t.circle(40)
t.circle(60)

14. VARIABLE

15. VARIABLE
A variable is a quantity that may change within the
context of a mathematical problem or
experiment.
Typically, we use a single letter to represent
a variable.
For example:
2 x + 5 y = 10

16. EXERCISE 5: USINGVARIABLE
import turtle
t = turtle.Turtle()
r = 5 # radius = 5
t.circle(r)
t.circle(r*2)
t.circle(r*3)
r = 20 # radius = 20
t.circle(r)
t.circle(r*2)
t.circle(r*3)

17. SHAPE(), PENUP(), PENDOWN()

18. PYTHON FUNCTION SHAPE(), PENUP(),
PENDOWN()
Shape(shapename) – Shapename can be ‘arrow’,
‘classic’, ‘turtle’ or ‘circle’
Penup() and Pendown() commands are used to move
around the screen
Pencolor(color) – Sets the color of the pen.
Pensize(size) – Sets the thickness of the pen.

19. EXERCISE 6: PENUP() & PENDOWN()
import turtle
t = turtle.Turtle()
t.shape("turtle")
t.stamp()
t.penup()
t.forward(30)
t.pendown()
t.stamp()
t.penup()
t.forward(30)
t.pendown()
t.stamp()

20. PROJECT OLYMPICS
import turtle
t = turtle.Turtle("turtle")
t.pensize(10)
t.penup()
t.setposition(-120, 60)
t.pendown()
t.color("blue")
t.circle(50)
t.penup()
t.setposition(-60, 0)
t.pendown()
t.color("yellow")
t.circle(50)

21. t.penup()
t.setposition(0, 60)
t.pendown()
t.color("black")
t.circle(50)
t.penup()
t.setposition(60, 0)
t.pendown()
t.color("green")
t.circle(50)
t.penup()
t.setposition(120,60)
t.pendown()
t.color("red")
t.circle(50)

22. CONDITIONAL STATEMENT

23. CONDITIONAL STATEMENT
 Conditional statements are used to check conditions and change the behavior of
the program accordingly.
 Syntax:
if EXPRESSION:
STATEMENTS
 The colon (:) is significant and required. It separates the header of the compound
statement from the body.
 The line after the colon must be indented (use four spaces for indenting).
 All lines indented the same amount after the colon will be executed whenever the
EXPRESSION is true.

24. CONDITIONAL OPERATOR
Meaning Python Symbols
Less than <
Greater than >
Less than or equal to <=
Greater than or equal to >=
Equal to ==
Not equal to !=

25. EXERCISE 7: EXAMPLE – IF .. ELIF .. ELSE..
import turtle
t = turtle.Turtle()
t.shape("turtle")
points = input(“Enter Points between 0 and 100: ")
Points = int (points)
if Points >= 90 and Points < 100:
t.left(90)
elif Points >= 80 and Points < 90:
t.right(90)
else:
t.left(0)
t.forward(100)

26. NR Computer Learning Center
1835W. Orangewood, Suite 200
Orange, CA 92868
(714) 505-3475
www.nrclc.com