Construct a Central Angle

Use the tools indicated to create 2 chords, construct perpendicular bisectors of each segment; the intersection of the bisectors is the center of the circle; finally draw two radii of the circle to create a central angle and report the size of the radius. {You need to select the points so that the angle is measured counter clockwise around circle; <point><center point><point>} You can hide construction lines by right clicking one line and selecting Hide Object. <CTRL><Z> can erase the previous step (sometimes).