Jawabanmu

2014-05-23T17:51:37+07:00
22 = 40/360 x 22/7 x 2 x r
22 = 1/9 x 22/7 x 2r
22 = 22/63 x 2r
22 x 63/22 = 2r
2r = 63
r = 63/2
r = 31,5