DC=a
AB=b
DA=CE=h
\sin{45}=\frac{h}{CB}
\frac{\sqrt{2}}{2}=\frac{8}{CB}
CB\sqrt{2}=16
CB=\frac{16}{\sqrt{2}}=\frac{16*\sqrt{2}}{\sqrt{2}*\sqrt{2}}=8\sqrt{2}
(EB)^2=(CB)^2-h^2=(8\sqrt{2})^2-8^2=128-64=64
EB=\sqrt{64}=8
(AE)^2=(AC)^2-h^2=10^2-8^2=100-64=36
AE=\sqrt{36}=6
AB=b=8+6=14
DC=a=6
Ob.=14+6+8+8\sqrt{2}=28+8\sqrt{2}
P=\frac{(a+b)h}{2}=\frac{(6+14)*8}{2}=80cm^2