Screenshot of Fit 3pt Arcs app for 12d Model. The app allows users to quickly and easily fit arcs to existing 3-pt strings. Shown is the ability to select many strings to process at once and control where the resulting strings are created. Options allow the user to close the arcs and create a point at the centre of the arc. Various modes are available for choosing how the centre point height is calculated from the original source points, including no height, minimum height, maximum height and average height.