In the Pythagorean theorem, a squared minim b squared equals c squared. If you apply that formule to question 2.
17^2-8^2 = 289 - 64 = 225 = 15^2.
Therefore, the answer to first question is yes
Then, for question 2, you do the same thing.
41^2 - 40^2 = 51
Here, 51 is not a square number. Most importantly it is not the square of9,
So this triangle is not right angled