The first one: let the unknown af = HC = X.

Then find CF=2.5X (angle C= angle c, EF‖GH, so triangle CHG is similar to triangle CEF) CF/CH=EF/HG according to similar triangles.

Then use a similar triangle to find AB, and you can find AB= 14.

(But in the eighth grade, similar triangles still want to go beyond the grade. )

According to the second method of graphic clipping and mending

Similar to the method of finding parallelogram area formula in the sixth grade of primary school

You can make vertical lines perpendicular to HG FA, AB EP and AB through C F E and CM respectively.

Congruent triangles can be used to find a PB.

Then find AB

If you have any questions, please ask.

Xiaoxiao and Liang will answer for you.