Respostas

2014-05-18T16:21:13-03:00
A²=b²+c²-2bc*cosA
a²=4²+5²-2*4*5*1/2
a²=21
a=V21


2p=4+5+V21
p=9+V21/2

A=Vp(p-a)(p-b)(p-c)
A=V9+V21/2(9-V21/2)(1+V21/2)(-1+V21/2
agora vc continua a conta pra reduzi-la porque to sem tempo