[radius, angle]
x An input point to be rotated   [+6,  0, *] -> [6.00,   0.000]

o Several stopping points:       [-2, +6, *] -> [6.32,   108.4]
                                 [-1, +5, *] -> [5.09,   101.3]
                                 [ 0, +7, *] -> [7.00,    90.0]
                                 [+1, +6, *] -> [6.08,    80.5]