PLZ HELP EVERYONE IGNORES ME)): I NEED HELP WITH QUESTION 3 AND 5 !!! PLEASE BRAINLIEST!!

Answer:
number 3 is 8 and number 5 is false
Step-by-step explanation:
the 45-45- sqr root theory would mean the number outside the radicand is the other side lengths, in this case, 8. so that would = x