Hi, just a simple question, i had a tough time drawing an arc or circle to make it tangent to the top horizaltal line, i used TTR for circle, it tangened with the vertical line but not the top line, when i use TTR for circle it will ask to specify Radius of the circle i just throw out the random R? what is the trick to calculate the radius? when used arc command it looks awkward. is there other tool that i can use?