Jawabanmu

2014-05-25T10:55:13+07:00
GL = 20 cm
p =25 cm
R2 = 9cm

tripel pythagoras: 20 25 9-x
4, 5, 3
3x5 = 15
15-9 = 6, jadi r1 adalah 6 cm
perbandingan = r1:r2
6:9 = 2:3
2014-05-25T12:44:55+07:00
L^2 = s^2 - (r1 - r2)^2
20^2 = 25^2 - (r1 - 9)^2
400 = 625 - (r1 - 9)^2
(r1-9)^2 = 625 - 400
(r1 -9)^2 = 225
r1 - 9 = akar 225
r1 - 9 = 15
r1 = 15+9
r1 = 24 cm

r1 : r2 = 24 : 9 = 8 : 3
( ^ = pangkat)
*maaf klo salah*