Help

Since ABCD is a unit square....its height = 1  an d its base = 1

So....its area = 1

And since EFGH  = 1/4 area of ABCD, then its base, FE, just must be 1/4

So.....that means that  BF + EA  = 3/4

So...the combined areas of BFGC  and EAHD must also be 3/4

But FGC  = 1/2 of BFGC   and EAH = 1/2 of EAHD

So...FGC + EAH  = (1/2) ( BFGC + EAHD)  = (1/2)(3/4) = 3/8

So...the area of quadilateral  AFCH  =

area of EFGH   + (area of FGC + area of EAH)   =

       (1/4 )          +      (3/8)        =

      (2/8)           +       (3/8)    =

                 5 / 8               

Thanks CPhill!