Answer: A and C
Step-by-step explanation: To see if it can be the side lengths of a right triangle we have to use the Pythagoras Theorem which is [tex]a^2 +b^2 = c^2\\[/tex]
C is always the largest length. Now we can sub the numbers in
[tex]5^2+\sqrt{6} ^2=\sqrt{31} ^2[/tex]
The squares and the square roots cancel each other out so we end up with
25+6=31
this is true so those are possible sides for a right triangle
Now for b:
[tex]\sqrt{5}^2 + \sqrt{5}^2 =50^2[/tex]
Again the squares and square roots cancel each other out
5+5=2500
This isn't true so it isn't the possible sides for a right triangle
Finally option C:
[tex]9^2+12^2=15^2[/tex]
81+144=225
225=225
This is true so it can be the side lengths that form a right triangle
