Jawabanmu

2014-03-13T09:01:57+07:00
Jarak=(12.12)+(9-4)(9-4) =144+25 =169 diakar =13 cm
2014-03-13T09:02:13+07:00
L2 = s2 - (R-r)2 12.12 = s2 - (9-4)2 144 = s2 - 25 s2 = 144 - 25 s2 = 119 s = √199 s = 10,9 cm