Jawabanmu

2014-05-20T17:04:24+07:00
Keliling =  \pi x r
105 = 3.14 x r
r = 105 : 3.14
r = 33.4

luas =   \pi  x r ^{2}
luas = 3.14 x (33.4) ^{2}
luas = 3.14 x 66.8
luas = 210