Answer:
as long as
[tex]a^2+b^2=c^2[/tex]
then it’s valid, soo...
the first one is not valid (5,6,sqrt 223)
the second one is Not valid (7,11,sqrt 175)
the third one is correct, since [tex]6^2+15^2=261[/tex]
and [tex]\sqrt 261 = 16.1554944214[/tex] (further info)
