Jawabanmu

2014-01-17T19:39:27+07:00
A. 1225
s x s = 1225
s = 35

3,14 x r x r = 1225
r^2 = 390
r = 19,75

3,9 : 7

b. 784
s x s = 784
s = 28

3,14 x r x r = 784
r^2 = 249,6
r = 15,8

3,95 : 7