Answer:

or

Explanation:
Since the legs are equal this is a 45-45-90 triangle.
The ratio of side length for a 45 45 90 triangle

where 1 is the legs length and sqr root of 2 is the length of the hypotenuse.
Since we are trying to find the length of the legs side we can set up a proportion.
We know the hypotenuse is 4 so our proportion looks like

Let see how far sqr root of 2 goes into 4.



so that means the answer for the legs length is

or
