104. If $p, q, r$ are in GP and the line $p x+q y+r=0$ forms a triangle with the coordinate axes, what is the area of the triangle if $p=2, q=4$ and $r=8$ ?

If four lines $a x \pm b y \pm c=0$ encloses a rhombus, then the area is

If the equation $2 h x y+2 g x+2 f y+c=0$ represents two straight lines, then the area of rectangle formed with the coordinates axes is