Area of Quadrilateral inside a rectangle

[songoku]

Homework Statement

Please see the picture below.

If AF = FB, BE = 4CE and the area of AGD = 100, find the area of CDGE

Relevant Equations

Not sure

I try to divide the area of CDGE into two areas of triangles by drawing line DE.

The ratio of area of triangles ABE and ECD = 4 : 1

The ratio of area of triangles ADG and DGE = AG : GE

The ratio of triangles ADG and AGF = DG : GF

Then I don't know what to do.

 

[anuttarasammyak]

Why don't you extend AE and DC and observe they cross ,say, at H ?

 

[songoku]

Why don't you extend AE and DC and observe they cross ,say, at H ?

I understand your hint. Thank you very much anuttarasammyak