from cs1graphics import *

numLevels = 8                             # number of levels
unitSize = 12                             # the height of one level
screenSize = unitSize * (numLevels + 1)
paper = Canvas(screenSize, screenSize)

small = unitSize/2               # minimal padding
big = screenSize-unitSize/2      # screensize - padding

poly = Polygon(Point(small,big), Point(big,big))   # bottom edge points
poly.setFillColor('gray')

x = big     # placement of top-right point
y = small   # placement of top-right point

# add two points for each level
for level in range(numLevels):
    poly.addPoint(Point(x,y))
    x -= unitSize
    poly.addPoint(Point(x,y))
    y += unitSize                 # move downward for next level

paper.add(poly)