Jawabanmu

2014-06-02T12:33:06+07:00
Keliling = π d
12.56 = 3.14 . d
d = 12.56 / 3.14
d = 4
r = 1/2 d = 2

Luas = π r²
Luas = 3,14 . 2 . 2
Luas = 12.56 

Jawaban = b
1 5 1
2014-06-02T12:37:03+07:00
K = 2.π.r
12,56 = 2 . 3,14 .r
12,56 = 6,28 .r
12,56 = r
6,28
2 = r

L = π × r²
   = 3,14 × 2²
   = 3,14 × 4
   = 12, 56 cm (b)
semoga membantu :)

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