This week we learned aboutcircles. With paper and pencil nearby, think about these questions beforelooking at the reference linked below. Given two circles, how many tangentlines can be drawn that are common to both, i.e. tangent to both circles? Do theradii of the circles change the answer? What other criteria could change theanswer? Now look at page 7 of this useful formula sheet: CircleDefinitions and Theorems.Does it match what you found? What other tidbits of information on thisthorough formula sheet do you find useful, interesting, surprising, orconfusing?