Jawabanmu

2014-03-31T20:19:24+07:00
R=5 l=πr^2 l=3,14x100 l=314 cm^2
2014-03-31T20:29:26+07:00
Sisi persegi = diameter lingkaran. jadi d = 10 cm
r = 1/2 d = 1/2.10 = 5 cm
rumus luas lingkaran =  \pi  . r^2
= 3,14 . 5^2
= 3,14 . 25
= 78,5 cm