Jawabanmu

2014-06-20T15:38:49+07:00
S= 1/2 klling segitiga
s= 1/2 (15+15+18)
s= 24
r= √s(s-a)(s-b)(s-c)/s
r= √24(24-15)(24-15)(24-18) /24
r= 4.5 cm