Jawabanmu

2014-06-18T22:33:29+07:00
Kll =  \pi .D
37,68 = 3,14 . D
37,68 = D
3,14
12 = D
6 = r

luas =  \pi . r^{2}
       = 3,14.  6^{2}
       = 3,14 . 36
       =113.04
2014-06-18T22:36:42+07:00
Keliling Lingkaran
37,68= 2.pi.r
37,68= 2.3,14.r
37,68= 6,28.r
r= 37,68/6,28 = 6 cm
Luas Lingkaran
pi.r^2
3,14.6^2 = 3,14.36 = 113,04 cm^2