Jawabanmu

2014-05-18T23:38:33+07:00
Panjang tali = keliling lingkaran + 2 x diameter
58 =  2.\pi.r  + 4r \\ 58=  2.\frac{22}{7} r+4r \\ 58= \frac{44r}{7}+4r \\ 58= \frac{58r}{7} \\ r=7