The center can be found using the midpoint formula: M=[(x1+x2)/2], [(y1+y2)/2]. For us, that looks like this: M = [(-2-14)/2], [(10-6)/2] which gives us M = (-8, 2). Now you have your center. To find the radius, use that midpoint (or center) and an endpoint to find out the distance between them (use the distance formula for that). The distance between those 2 coordinates is 10. So your center is (-8,2) and your radius is 10