vertices = [(100, 400), (200, 400), (150, 500)]
# Create a polygon annotation on the page
annotation = page.add_polygon_annot(vertices)
# Set the annotation's properties (optional)
annotation.set_border(width=1.5)
annotation.set_opacity(0.5)
popup_rect = fitz.Rect(300, 400, 500, 500)
annotation.set_popup(popup_rect)
annotation.set_info(None, 'content', 'title')