Jawabanmu

2014-06-05T17:15:32+07:00
L = pi . r^2
314 = 3,14r^2
r^2 = 314 / 3,14
r^2 = 100
r = 10 cm

d = 2r
d = 2 x 10
d = 20 cm
2014-06-05T17:16:27+07:00
Luas = 3,14 x r x r
314 = 3,14 x r x r
r2 = 314 : 3,14
r2 = 100
r = 10
diameter = 2 kali r
d = 20
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