## anonymous 4 years ago length of C...

1. anonymous

|dw:1327270172508:dw|

2. anonymous

$c^2=b^2+a^2-2ab \cos(180-\beta)$

3. anonymous

because i need the angle between a and b right? so $\sqrt{a ^{2}+b ^{2}-2abcos \beta}$ would be wrong, correct?