Jawabanmu

2014-02-05T20:08:49+07:00
L = π r²
706,5 = 3,14 x r²
r² = 706,5/3,14
r² = 225
r = √225 = 15 cm
⇒k = 2 π r
      = 2 x 3,14 x 15 = 94,2 cm
2014-02-05T22:47:40+07:00
L = πr^2
r^2 = L/π
r^2 = 706,5 / 3,14
r^2 =225
r =√225
r =15

K = 2πr
   = 2 x 3,14 x 15
   =94,2 cm