In a 45-45-90 triangle, what is the length of the hypotenuse when the length of one of the legs is 5 in.?

5√5 in.

5√2 in.

2√5 in.

√5 in.

it is an isosceles triangle is one leg is 5 then so is the other.

It is right angles so not use Pythagorases theorum.