Jawabanmu

2014-05-20T15:01:10+07:00
Luas lingkaran = 3,14 X 81 = 254,34
keliling = 2 X 3,14 X 9 = 3,14 X 18 = 56,52
2014-05-20T15:04:21+07:00
R = 9cm

Luas lingkaran
=πr²
=3,14 x 9²
= 254,34 cm²

Keliling lingkaran
=2πr
=2 x 3,14 x 9
=56,52 cm