Respuesta :

Answer:
a=9

Explanation:
The triangle is a 45-45-90 triangle, so the sides have a 1-1-root 2 ratio. So, if 9 root 2 is to root 2, then find a to 1. You can solve this by setting up the ratio and solving for a:
a/1=9root2/root2
a/1=9
a=9