>>11156146well I'm not going to write it all out for you
but you can find the intersections of all of the black lines by typing stuff like "intersection of -2x+1 and x+1/2" into wolfram alpha
once you have all those intersection points, you can find the equations for the red lines by typing "line through (1/3,5/6) and (3/5,1/5)" etc.
after that you can find the intersections of the red lines in the same way
these intersections are (143/345,221/345), (53/128,41/64) and (75/181,116/181)
then you can find the area of the triangle by typing "area of triangle (143/345,221/345), (53/128,41/64), (75/181,116/181)"
and it will tell you it's 1/15985920, which is about 6.2555E-8, which is the same result geogebra gives me (see pic)
you can do all these steps by hand of course, but it's just a lot of work
