Externally erect a square on the side 
. Now join the new vertices 
and 
of this square with the vertex 
, marking the points of intersection 
and 
. Next, draw the perpendiculars to 
through 
and 
. These lines intersect 
and 
respectively in 
and 
. This results in the 
-inscribed square 
.
The triangle has area
 |
where 
is the area of the reference triangle.
