Answer:
Since, a 45°-45°-90° triangle is a special type of isosceles right triangle, where the two legs are congruent to one another and the non-right angles are both equal to 45 degrees.
In 45°−45°−90° triangle
Sides are in the proportion

then,
the measures of the sides are

The length of hypotenuse=
times the length of the leg. ....[1]
Given: length of hypotenuse = 128 cm.
then,
from [1] we have;
128 =

or
=

Simplify:
cm.
Therefore, the length of one leg of the triangle is;
cm.