Answer
21
Work Step by Step
Step 1. See graph, sketch the triangle with the given vertices.
Step 2. Recall the determinant formula for the area of a triangle:
$\begin{array}( \\A=\pm\frac{1}{2} \\ \\ \end{array}
\begin{vmatrix}0 &0&1\\6&2&1\\3&8&1 \end{vmatrix}$
Step 3. Evaluate the determinant (row1 expansion for this case)
$A=\frac{1}{2}|(1)(6\times8-2\times3)|=21$
