.</span>
   <span class="identifier">T</span> <span class="identifier">max</span> <span class="special">=</span> <span class="identifier">arc</span><span class="special">;</span>                                 <span class="comment">// radius can't be larger than the arc length.</span>

   <span class="comment">// Accuracy triples at each step, so stop when just over one-third of the digits</span>
   <span class="comment">// are correct, and the last iteration will polish off the remaining digits:</span>
  