Respostas

2014-08-25T22:45:28-03:00
2160=(n-2).180
2160=180n-360
-180n=-2160-360
-180n=-2520 (-1)
180n=2520 \frac{14(14-3)}{2}
n=2520/180
n=14

d= \frac{14(14-3)}{2}
d= \frac{154}{2}
d=77