size(600, 600);

int numLevels = 5;
float stepSize = height/(1+numLevels);

beginShape();
vertex(0.5*stepSize, height-0.5*stepSize);
vertex(0.5*stepSize, 0.5*stepSize);
// right side from top to bottom
for (int level = 0; level < numLevels; level++) {
  vertex(stepSize*(1.5+level), stepSize * (0.5+level));
  vertex(stepSize*(1.5+level), stepSize * (1.5+level));
}
endShape(CLOSE);