import turtle
import random
import math
screen = turtle.Screen() 
screen.bgcolor('yellow')
#Starting position and rate
ballX=0
ballY=0
dX=2
# create turtle, hide it, move to start position
ball = turtle.Turtle()
ball.penup()
ball.shape('circle')
# Animate!
while ballX<300:
  ball.goto(ballX,ballY)
  ballX+=dX