Jawabanmu

2014-02-06T20:17:15+07:00
3,14 x r² = 706,50
r² = 706,50 : 3,14
r² = 225
r = 15
2014-02-06T20:17:37+07:00
Luas lingkaran = phi r kuadrat
706,50 = 3,14 r kuadrat
706,50 / 3,14 = r kuadrat
225 = r kuadrat
 \sqrt225 = r
15 = r
 jadi jawaban ny (c) . 15