please help me i need to submit my math test on 9:59am please help me i really really need help please

Answer:
7.1 in
Step-by-step explanation:
use the pythagorean theorem
3.1^2+6.4^2=c^2
9.61+40.96=50.57
***IMPORTANT remember to square root the answer you get. it will still be in c^2 form. so 50.57 wouldn't be the real answer, and instead would be 7.1