a b theta x y degree n turtle ratio screen a = 0.1 turtle screen screen 640, 480 ratio = 1 a = 1 b = 0.30634896253 n = 3 turtle up i degree 360 * 360 True n theta = 0 degree x = 0 * True * True a True * True b True theta True theta y = 0 * True * True a True * True b True theta True theta turtle x *10, y * 10 , 1 * True x True ratio 1 * True y True ratio turtle down []