Click a From or To bearing button then the map to change it.
0: => Emo: from Sanctuary, SSE
1: => Rob: from Boston Common, W
2: => Mike: from Boston Public Library, NNE
3: => Duley: from Trinity Tower, WNW toward Oberland Station
4: => Brian: from Coast Guard Pier, due N

Enter new parameter, then press TAB.
Arc Size:
Arc Trans: