Let EC = 3x and FC = 4x.
DE=EF=5x (Pythagorean theorem)
AB=DC=8x
Angle Baff+angle BFA=90 degrees, angle EFC+ angle BFA= 180 degrees-angle AFE=90 degrees.
Angle BAF= angle EFC
BF/AB=3/4
BF=6x
AD=BF+FC= 10x
AD？ +DE？ =AE？
100x？ +25x？ =500
x=2
AD= 10*2=20，AB=8*2= 16
Circumference =(20+ 16)*2=72