Jawabanmu

2014-02-11T20:18:57+07:00
K=2. \pi .r
157 cm = 2.3,14.r
 \frac{157}{2.3,14} = r
 \frac{157}{6,28} = r
25 cm =r
Jadi, jawabannya b. 25 ^_^

2014-02-11T20:19:33+07:00
K=2..r
157 cm = 2.3,14.r
 = r
 = r
25 cm =r