Please see attached

BN=4 units

AN is an angle bisector

AB + AC = 30 units

m(ABC) = 90 degrees

What is the area of the triangle ABC?

I tried having three equations with three unknowns from phtagors plus the side ratios of angle bisector formulas but i am getting equations to 4th degree, which is not supposed to happen in this test, there must be a much simpler and nicer solution

the answer was given as 60