A right angled triangle has a hypotenuse of "4+√3" and sides “a” and "2- √3", what is a

A right angled triangle has a hypotenuse of 4+ √3 and sides “a” and 2- √3, what is a?
Working out the length of “a” I got √(26+4√3), apparently this is wrong and it is 26+4√3. What have I done wrong?

a^2 + (2-√3)(2-√3) = (4+√3)(4+√3)
a^2 + 4+3-4√3 = 16+3+8√3
a^2 = 12+12√3
a = √(12+12√3)

You have put 4+√3 squared plus 2-√3 squared = to A squared

you should put the hypotenuse squared equal to A squared 2-√3 squared.

The answer "26+4√3" is also wrong as it should be "root of 12+12√3"

hope this helps