△ ACB is an isosceles right triangle.

CF = x

∴AE=EP=CF=x PF=BF=3√2-x

The ∴ area of a rectangle PECF =PF*CF=(3√2-x)x

The area of RT△AEP =AE*EP/2=x? /2

The area of RT△PFB =PF*FB/2=(3√2-x)? /2