Python输入输出练习，运算练习，turtle初步练习

print("hello word")

name=input("输入姓名:")
print("{}同学，学好Python，前途无量！" .format(name))

a=input("请输入数字a:")
b=input("请输入数字b:")
c=float(a)+float(b)
print("数字{}加上数字{}等于{}".format(a,b,c))

import math
a=input("输入边长a：")
b=input("输入边长b：")
c=input("输入边长c：")
p=(float(a)+float(b)+float(c))/2
s=math.sqrt(p*(p-float(a))*(p-float(b))*(p-float(c)))
print("边长分别为a={},b={},c={}的三角形的面积为{}".format(a,b,c,s))

radius=input("输入半径：")
area=3.1415*float(radius)*float(radius)
print("半径是{}的圆的面积是{:.2f}" .format(radius,area))

from turtle import *

for i in range(4):
    pu()
    goto(0,-100)
    pd()
    circle((i+1)*20)

import turtle
for i in range(5):
    turtle.forward(200)
    turtle.right(144)

import turtle
turtle.fillcolor("yellow")
turtle.begin_fill()
for i in range(5):
    turtle.forward(200)
    turtle.right(144)
turtle.end_fill()