Answer:
5√2
Step-by-step explanation:
What we know)
The legs in a 45-45-90 triangle are the same
The Pythagorean Formula is a²+b²=c² where a and b are the legs ands c is the hypotenus
What we can find)
Both the legs are 5
5²+5²=c²
25+25=c²
50=c²
c=5√2
