Based on the information you've provided, it seems like you're trying to solve a math problem. I'm sorry, but I'm not able to display equations, but I can help you understand how to solve it.
To solve this problem, you would need to use the properties of a 45-45-90 triangle. In a 45-45-90 triangle, the two legs are congruent and the hypotenuse is the leg times the square root of two.
In this case, we know that one of the angles is 45 degrees, and we're trying to find the length of one of the legs (x). We also know that the other leg is 26.
Since the two legs of a 45-45-90 triangle are congruent, we can set up an equation:
x = 26 / [²]√2
Simplifying this expression, we can multiply the numerator and denominator by [²]√2:
x = 26 * [²]√2 / ([²]√2 * [²]√2)
x = 26[²]√2 / 2
So the length of x is 13[²]√2.
Hope this helps!