Jawabanmu

Jawaban paling cerdas!
2014-01-22T15:24:29+07:00
2phiR=30
R=30/2phi

2R=60/2phi
 jadi, keliling skrng 60 CM 
2014-01-22T15:39:31+07:00
30 = 2. pi .r
15 = 3,14 .r
15/3,14 =r
4,7 =r
dikali 2 maka r = 9,4 cm
maka keliling = 2.3,14 .9,4 cm = 59,032 cm