how to fill in shapes in tkinter after code example

Example 1: rectangle in tkinter

from tkinter import *

root = Tk()

c = Canvas(root)
c.pack()
c.create_rectangle(100, 100, 200, 200)

root.mainloop()

Example 2: tkinter draw squaer

from Tkinter import *
master = Tk()

w = Canvas(master, width=250, height=200)
w.create_rectangle(0, 0, 100, 100, fill="blue", outline = 'blue')
w.create_rectangle(50, 50, 100, 100, fill="red", outline = 'blue') 
w.pack()
master.mainloop()