Question 773685
For the points A(1,0,1), B(-2,4,3), and C(1,2,-1), find:

The area of the triangle ABC
----------------
Find the side lengths.
{{{AB = sqrt(diffz^2 + diffy^2 + diffx^2) = sqrt(2^2 + 4^2 + 3^2) = sqrt(29)}}}
Find AC and BC.
---
Then either use Heron's Law, or
Find an angle using the Cosine Law.