Distance between  x = a1*cos(t)+b1, y = a2*sin(t)+b2  and  x = h1*cos(t)+k1, y = h2*sin(t)+k2
a1 b1 a2 b2
h1 k1 h2 k2

                      N   N = 2 round to cents  N = -2 to hundreds
click+ and click++ are more accurate but take longer (10×, 100×)
examples