Jawabanmu

2014-06-08T09:26:07+07:00
K = πd
37,68 = 3,14 × d
d = 37,68 : 3,14
d = 12 cm
r = 6 cm

L = π r²
L = 3,14 × 6²
L = 3,14 × 36
L = 113,04 cm²
2014-06-08T09:41:53+07:00
K lingkaran =  \pi d /  \pi 2r
37,68 = 3,14 X 2r
37,68/3,14 = 2r
 12 = 2r
12/2 = r
6 = r

L lingkaran =  \pi X r X r
L lingkaran = 3.14 X 6 X 6
L lingkaran = 113,04