the picture in the attached figure
we know that
if ABC is an isosceles triangle
then
AB=BC
angle A=angle C=45 degrees
and
triangle ABD and triangle BDC also are isosceles triangles
AD=BD=x
DC=BD=x
the hypotenuse AC is equal to
To find the length AB applying the Pythagorean Theorem
remember that AB=BC
therefore
the answer is
the length of one leg of the large right triangle in terms of x is equal to
