Quadrea? I had enough trouble with area!

Consider a triangle with side lengths 2, 3 and 4.

Let $Q_1, Q_2, Q_3$ denote the numerical values of the square of the side lengths this triangle.

We can think of quadrea , $A$ as $16$ times the area of a triangle that can be expressed in terms of its quandrances , $Q_1, Q_2, Q_3$ .

Given that $A$ can be expressed as $4Q_1 Q_2 - (Q_1 + Q_2 - Q_3)^2$ .

Find the quadrea of this triangle.