Python输入输出练习，运算练习，turtle初步练习

print("Hello Word")

a1 = input("a1:")
a2 = input("a2:")
sum = float(a1)+float(a2)
print("第一个数{0}加第二个数{1}的和是{2}".format(a1,a2,sum))

import math
a1 = input("a1:")
a2 = input("a2:")
a3 = input("a3:")
p =(float(a1)+float(a2)+float(a3))/2
d=float(p)
area = d*(d-float(a1))*(d-float(a2))*(d-float(a3))
b=float(area)
c=math.sqrt(b)
print(c)

Circle = input("圆的半径 :")
area = 3.14 * float(Circle)*float(Circle)
print(area)

import turtle
a = 0
while a < 5:
    turtle.forward(200)
    turtle.left(144)
    a = a + 1

from turtle import *
fillcolor("yellow")
begin_fill()
while True:
forward(200)
left(144)

if abs(pos())<1:
break
end_fill()

import turtle
turtle.pensize(8)
turtle.circle(10)
turtle.circle(20)
turtle.circle(40)
turtle.circle(80)
turtle.circle(160)