Respuesta :

The pythagorean theorem states that for any RIGHT-ANGLED TRIANGLE, the relationship between the side lengths are A²+B²=C², where C is the hypotenuse :P

Which means that it can only be applied on right angled triangles~
So your answer would be B, a right-angled triangle.

Ask me if you are unsure about anything <3
It has to be triangle B.

You only use the pythagorean theorem for right triangles (triangles with one 90 degree angle).