Solution
= Solution
$(b-a)\times(c-a)=(-1,0,0)\times(-1,-1,1)=(0,1,1)$. Thus one choice is $\hat n=(0,1,1)/\sqrt2$ and $\beta=\sqrt2$.
= Solution
$(b-a)\times(c-a)=(-1,0,0)\times(-1,-1,1)=(0,1,1)$. Thus one choice is $\hat n=(0,1,1)/\sqrt2$ and $\beta=\sqrt2$.