Respostas

2013-07-09T11:03:37-03:00
cos 30 = h/40

1/2 = h/40

h = 20 cm

comprimento da base:

cos 30 = 0,5b/40 

V3/2 = 0,5b/40

b = 40V3

A=b*h

40V3.20/2 = 40V3.10 = 400V3
3 5 3