Jawabanmu

2014-05-25T19:04:13+07:00
R = 21
K = 2πr = 2 x 22/7 x 21 = 132 cm
jarak = 132 m = 13200 cm
putaran roda = 13200 / 132 = 100 kali
2014-05-25T19:08:35+07:00
132 m = 13200 cm
K lingkaran = 2 x 22/7 x r
roda berputar = 13200 = 2 x 22/7 x 21
                    = 13200 = 132
                    = 13200/132
                    = 100 kali