Jawabanmu

2014-04-28T08:54:05+07:00
Rumus luas permukaan Bola : 4 phi R^2
1386 cm^2= 4. 22/7. R^2
1386 cm^2= 12,5. 4^2
1386:12,5=R^2
110,88=R^2

110,88=R
10,5=R
Kira-kira gitu deh..Semoga membantu, ya...
2014-04-28T08:58:16+07:00
L  =  4  π  r2
1386 = 4 x 22/7 x r²
1386 : 88/7  = r²
1386 X 7/88  = r
²
110,25 = r²
10,5 = r
²