We have proved that P-circles in the disk are E-circles, and con- versely. We also showed how to construct the E-center of a P-circle given its P-center. Show conversely, given an E-circle in the disk and its E-center, how to construct its P-center. (Hint: It comes down to constructing the P-midpoint of a certain E-segment that is contained in a diameter of the disk.)