Why is it that all right triangles aren't true? Like with c² = a² + b². If it has a right angle, they all are right triangles, right? I know how to use the Pythagorean theorem but not why all right triangles aren't true.
The Pythagorean theorem is true for all right triangles.
(one leg)2 + (other leg)2 = (hypotenuse)2
This equation is always true.
The hypotenuse is, by definition, the side across from the 90º angle.
The legs are just sides not across from the 90º angle.
What made you think that it wasn't true for all right triangles?