Answer:
The first one
Explanation:
Use the pythagoras theorem=a ^2+b^2 =c^2
Use a is 9 b is 40 because the largest value is always the hypotenuse and the hypotenuse is always c.
so you do 9 squared add 40 squared to find c squared.
Square root the answer and you get 41 so it is a pythagoras triple