Jawabanmu

2014-06-17T18:11:15+07:00
Πr² = 7850
22/7*r² = 7850
22*r²    = 54950
r²         = 2497,7
r          = √2497,7
2014-06-17T18:36:13+07:00
7850 = πr²
7850 = 3,14r²
r² = 24649
r = 157
maaf kalau salah