Jawabanmu

2014-02-21T21:22:53+07:00
Panjang busur MN = sudut MON / 360drjt x 2 \pi r
31,4 = 1/5 x 2 x 3,14 x r
31.4 = 1/5 x 6,28 x r
r = 31,4 Per 1/5 x 6,28
r = 25