Question

Lingkaran luasnya 7.850 cm2 hitung keliling lingkaran.

Answer 1

Lo=πr²
7850=3,14xr²
7850/3,14=r²
2500=r²
√2500=r
50=r

Ko= 2πr
=2x3,14x50
=100x3,14
=314 cm

Answer 2

L =
7850 = 3,14 x r²
7850 : 3,14 = r²
2500 = r²
50 = r

K =
   = 2 x 3,14 x 50
   = 314 cm