A triangle is NOT said to be a right-angled triangle if its sides measure:

5 cm, 7 cm and 9 cm

By carefully observing all the options. We find that,

Except option 2 all others are triplet and follow pythagoras theorem.

Option2 :- 5 cm, 7 cm and 9 cm

P² + B² = H²

5² + 7² ≠ 9²

So, Triangle with sides 5 cm, 7 cm and 9 cm is not right angle triangle.