Let  and  be two nonconcentric circles and let I and E divide SensedMagnitude(AB) internally and externally in the ratio a/b. Then I and E are called the internal and the external centers of similitude of the two circles c1 and c2

The routine assigns to obj a list of two elements where the first element is the internal center of similitude, and then second element the external center of similitude.

For a detailed description of the centers of similitude obj, use the routine detail (i.e., detail(obj))

The command with(geometry,similitude) allows the use of the abbreviated form of this command.

similitude:   "hint: the external and internal centers of similitude are the same"