They are both drawn as right angled triangles so if we can constract them then they should obey pythagoras theorem
First traingle:- 8^2 = 64
7^2 + 6^2 = 49 + 36 = 85 so this does not obey the theorem and you cant draw it.
Second traingle: 9^2 = 81 and 5^2 + 7^2 = 25 + 49 = 75 so we cant draw that one either.
