Because: quadrilateral ABCD is a parallelogram.

So: AB//CD means: ∠ABC+∠BCD= 180 degrees, ∠AEB=∠EBC, ∠DEC=∠BCE.

Because: Be and CD are equally divided into ∠ABC and ∠BCD respectively.

So: ∠EBC+∠ECD=90 degrees ∠ Abbe =∠EBC, ∠BCE=∠ECD.

Because: BE= 12cm, CE=5cm.

So: BC= 13cm.

Because: ∠AEB=∠EBC, ∠DEC=∠BCE, ∠ Abe =∠EBC, ∠BCE=∠ECD

So: ∠ Abbe =∠AEB, ∠ Dirk =∠DCE, namely: AB=AE, DE=DC.

So: AB+DC=AE+DE=AD= 13cm.

So the perimeter of parallelogram ABCD is (AB+CD)+BC+DA =13+13+13 = 39cm.

As shown in the figure, if e makes EF perpendicular to BC, then:

Because: triangle BEC is a right triangle.

Therefore, EF*BC=BE*CE means: EF* 13= 12*5, then: EF=60/ 13.

Therefore, the area of parallelogram ABCD is: 13*60/ 13=60 cm2.