Keliling 62,8 Berapakah luas lingkaran

[tex]k = 2\pi \times r \\ 62.8 = 2 \times 3.14 \times r \\ 62.8 = 6.28 \times r \\ r = \frac{62.8}{6.28} = 10 \\ luas = \pi \times {r}^{2} \times 3.14 \times 10 \times 10 =314 {cm}^{2} [/tex]