Respostas

2014-06-09T13:01:41-03:00
B/4 = c/2        b+c =90⇒ b=90-c

90-c/4 = c/2
2(90-c) = 4c
180-2c = 4c
6c = 180 ⇒ c= 30

b+c = 90 ⇒b+30 = 90 
b = 90-30 
b = 60