Pre test help

Yep.....it's a multiple  [of 9]  of the basic triad   3 - 4 - 5

All multiples of the basic Pythagorean triads are themselves Pythagorean triads

Yes, it is, because:

45^2 =36^2 + 27^2. They are called "Pythagorean "triple".

is 27, 36, 45 a pythagorean triad

$\begin{array}{|rcll|} \hline \sqrt{27^2+ 36^2} = 45 \qquad \text{yes 27, 36, 45 a pythagorean triad} \\ \hline \end{array}$