Jawabanmu

2014-05-17T05:40:16+07:00
4 x \pi x r2 = 4 x 22/7 x 7 x 7 = 616 cm
2014-05-17T06:29:02+07:00
Rumusnya = 4.π. r²
 
Lp = 4 . 22/7 . 7²
Lp = 4. 22/7 . 49
Lp = 4 . 22 . 7
Lp = 616 cm²

:D biar lebih pasti silahkan dkoreksi :)