Jawabanmu

2014-05-24T21:07:44+07:00
2014-05-24T21:46:58+07:00
Pertama kita cari r2, 
r2 = (akar 30^2-24^2) - 10
r2 = akar(900-576) - 10
r2 = akar324 - 10
r2 = 18-10
r2 = 8

r1^2*phi : r2^2*phi
10^2 : 8^2
100 : 64
25 :16

semoga membantu ya... :)