How do you find hypotenuse of a cube

as the length of the diagonal of the n-cube of side length 1. A demonstration of the Pythagorean theorem. Two squares built on the edges of a right triangle and four copies of the triangle exactly fill a large sqwuare that is also filled by four copies of the triangle and a square built on the hypotenuse.

1935/10,000= 387/2000the answer to the question is c