JavaScript must be enabled in order to use this site.Please enable JavaScript in your browser and refresh the page. To Modify an Arc's Sweep Angle Select the Modify Arc Angle tool (Drawing > Home > Placement > Arc Tools split button). Select the arc close to the end to modify. Enter a data point to lengthen or shorten the arc. Shortening and lengthening of an arc using Modify Arc Angle tool Parent topic: Modify Arc Angle