...I'm trying to use the scatter graph to draw out the extent of an arc, for which I know the radius and the length of the arc itself. These are the only two 'knowns' I have, but from these I can of course work backwards to understand the length of the arc in degrees etc. What I'm struggling with is a way to populate a table of Cartesian X,Y coordinates from which I can then plot the arc perfectly in the graph without it sloughing off as below (it should form a perfect arc, not :

Any and all help gladly recieved!