5. AB, PΔABM - ?

AE = AF = 5, ME = MF = 11 (отрезки касательных, проведённых из одной точки). AB = AE + EB = 5 + 5 = 10. BM = BF + FM = 5 + 11 = 16. AM = AE + EM = 5 + 11 = 16. PΔABM = AB + BM + AM = 10 + 16 + 16 = 42. AB = 10.