To bring up the image click the Green flag
This initially begins with a yellow backdrop. When going to "Pen" one large black dot is placed at x=0, y=0. Then, using trigonometry functions of "sin" and "cos", 360 radial white lines are drawn to overlay a white semicircle. Two large dots complete the black and white zones with two smaller ones overlaid to finish the design. Using sin and cos functions of increments of 1 degree leaves some black showing through hence 360 half degrees.
