P (3,0,1)
Q (1,2,-1)
R (2,-1,1)
formula used 1/2 |PR x PQ|
PR (-1,-1,-1)
PQ (-2,2,-3)
PRxPQ (5,-1,-4)
so the area is 1/2 |0| = 0?
Okay the correct cross product of pr x pq is (2,-2,-4)
I know the formula is 1/2 |pr x pq|
Now to calculate the area of the triangle I forget if it's the magnitude or simoply absolute value?
If it's the magnitude then the answer should be
1/2 | square root 24 |