The sides of a right angled triangle measure (√8 - 1 ) units and (√8 - 1 ) units in length . Calculate the length of the hypotenuse. Leave your answer in simplest surd form .

If two legs of the right triangle are equal (let they equal to x), then, according to the Pythagorean theorem, the hypotenuse equals √(x² + x²) = √(2x²) = x√2.

In this case, x = √8 - 1, then x√2 = √16 - √2 = 4 - √2