2. Let the diagonal intersection PE+PF=AE+E0=AO=2 root number 2.

3. 1:2

4. isosceles trapezoid

Extend AD and CE to point f

Angle DCA= Angle DAC, AF=FC

AD=CE

FD=FE

FD/AF=FE/FC

That is, DE‖AC and AD=CE are isosceles trapezoid.

S= 1/2h(AC+DE), while h= 12/5 and DE=7/5.

S= 192/25

5. Parallelogram

EG=FE, PQ‖BC, triangle PGF and triangle EGN are congruent.

That is PG=GN.

Triangle PQG and triangle MNG are congruent

PQ=MN，PQ‖BC。

The quadrilateral PMNQ is a parallelogram.