luas lingkran yg kelilingnya 12,56cm dengan q 3,14

12,56 ÷ 3,14 = 4 cm ( d )
3,14×2×2 = 12,56 cm2

Please, let me answer your question :)
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Mapel : Matematika
Tentang : Bangun Datar
Pertanyaan yg diajukan : 1
Pembahasan :

Diketahui :
- Keliling (K) : 12,56 cm

Ditanya :
- Luas (L)

Cara :

[tex]k = 2 \times \pi \times r \\ \\ 12.56 = 2 \times 3.14 \times r[/tex]

[tex]12.56 = 6.28 \times r \\ \\ r = \frac{12.56}{6.28} \\ \\ r = 2 \: cm[/tex]

[tex]l = \pi \times {r}^{2} \\ \\ l = 3.14 \times 2 \times 2[/tex]

[tex]l = 6.28 \times 2 \\ \\ l = 12.56 \: {cm}^{2} [/tex]

Jadi, luasnya adalah 12,56 cm²

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✚ Heil Manstein! ✚