输入输出练习

n1=input('输入一个数字')
n2=input('输入一个数字')
n3=float(n1) + float(n2)
print (float(n3))

n1=float(input('输入三角形边长1'))
n2=float(input('输入三角形边长2'))
n3=float(input('输入三角形边长3'))
s=(n1+n2+n3)/2
area = (s*(s-n1)*(s-n2)*(s-n3))**0.5
print('三角形面积：%0.2f' %area)

r=float(input('请输入圆的半径'))
area=3.1415*r*r
print(area)

　　

import turtle
turtle.color('red')
turtle.forward(500)
turtle.right(144)
turtle.forward(500)
turtle.right(144)
turtle.forward(500)
turtle.right(144)
turtle.forward(500)
turtle.right(144)
turtle.forward(500)

　　

import turtle
turtle.pensize(3)
turtle.circle(15)
turtle.circle(35)
turtle.circle(55)
turtle.circle(75)
turtle.circle(95)
turtle.circle(115)
turtle.circle(135)

　　

import turtle
turtle.color('red')
turtle.begin_fill()
turtle.fillcolor('red')
turtle.forward(500)
turtle.right(144)
turtle.forward(500)
turtle.right(144)
turtle.forward(500)
turtle.right(144)
turtle.forward(500)
turtle.right(144)
turtle.forward(500)
turtle.end_fill()