Jawabanmu

2014-05-08T16:59:12+07:00
L² = p²  - (R + r)²
34² =30² - (R + 5)²
1156 = 900 - (R + 5)²
1156 - 900 = (R + 5)²
256 = (R + 5)²
√256 = (R + 5)²
16 = (R + 5)
R + 5 = 16
R = 16  - 5
R = 11