'''
Demo_3 implements drawing simple shapes by using module "shape"
uses simple function define
implements simple doctest
--just open the terminal, get to the father directory of this Demo,
and python it adding parameter -V at the end of the command line
then the test will begin
'''
import shape
shape.rectangle(5,10)
print()
print()
shape.square(1)
print()
print()
shape.triangle(10)
