I would start by using the Pythagorean theorem to find the length of side AD first.
Since side AD is the longest side, it is going to be C squared in the equation.
Your equation should look like this:
( 25^2 )+( 18^2 )=( C^2 )
625+324= C^2
949= C^2
C is approximately 30.8 which means side AD is approximately 30.8cm long.
Next subtract the length of AE from AD to find ED.
30.8-26= 4.8 cm
ED= 4.8 cm
Now we are going to use the Pythagorean theorem again to find the length of BE.
Your equation should look like this:
( 20^2 )+( B^2 )= ( 26^2 )
400+( B^2 )= 676
B^2=279
B is approximately 16.7 meaning ED is 16.7 cm long
ED=4.8cm
BE=16.7cm