This program computes the area of a triangle with coordinates

, and , which is given by the value (absolute) of the following determinant
\[
\frac{1}{2}
\begin{vmatrix}
x_{1} & x_{2} & x_{3}\\
y_{1} & y_{2} & y_{3}\\
1 & 1 & 1
\end{vmatrix}
\]
Now ... the basic principle of modern mathematics is to achieve a complete fusion [of] 'geometric' and 'analytic' ideas.- Jean Dieudonné

FUNCTIONS