Jawabanmu

2014-09-09T16:57:10+07:00
R1/pr1 = r2/pr2
1/7 = 2/pr2
dikali silang = pr1 = 14
jadi panjang r1 = 14 cm
2014-09-09T16:57:23+07:00
R1 : r2 =1:2
maka
jika dik r1 = 7cm
r2 X 1 = r1x 2
r2 =7 x2
r2 = 14