Respuesta :

45 45 90 triangle
legs are x and hypotonuse=x√2
10=furst x
10=x
hypotonuse=10√2
that hypotonuse is the leg of the other triangle
the hypotonuse is √2 times that
10√2=x of bigger triangle
hypotonuse=x√2=10√2 times √2=10*2=20

answer is 20 units