Let $A = (-1,1,2),$ $B = (1,2,3),$ and $C = (t,1,1),$ where $t$ is a real number.  Find the smallest possible area of triangle $ABC.$
Question:
Let $A = (-1,1,2),$ $B = (1,2,3),$ and $C = (t,1,1),$ where $t$ is a real number.  Find the smallest possible area of triangle $ABC.$
Answer:
Let's think step by step.

user
\frac{\sqrt{3}}{2}
Let $A = (-1,1,2),$ $B = (1,2,3),$ and $C = (t,1,1),$ where $t$ is a real number.  Find the smallest possible area of triangle $ABC.$
train