need help in laying out arc. using a clock face i will try to explain. the line from 12 to 6 is the dia 1/2 of that is 48ft or the rad from 12 stepping down in 1 ft increments and running at a right angle can i get a lenght from the 12 to 6 axis? say from the arc i am coming back 15ft 6in the lenght from the axix line to the arc is? now move up the axis 1 ft what is that lenght? when you finally reach the arc the lenght from axis will be zero. can you get a formula to work?