The techniques below show a variety of methods of accurate positioning.
There are shorter ways to accomplish the last two cases in the diagram – see if you can find the way.
The videos below will show you several 2D tricks…
HOW TO POSITION A CIRCLE OR ARC THROUGH TWO POINTS TO CREATE ONE SHAPE:
HOW TO DRAW A CIRCLE OR ARC THROUGH POINTS:
HOW TO MOVE A CIRCLE SO THAT IT’S TANGENT TO ANOTHER CIRCLE: