Jawabanmu

2014-04-06T20:52:47+07:00
D² = p² - ( R + r )²
20² = p² - ( 9 + 6 )²
400 = p² - ( 15² )
400 = p² - 225
pindah ruas
400 + 225 = p²
√625 = p²
25     = p
Hasilnya 25 :) ada options nya?

2014-04-06T21:10:55+07:00