The pythagorean theorem is true for all similar triangles

No. It is not true for all similar triangles.

Step-by-step explanation:

Pythagorus theorem is generally used to find the third side by using the other two sides of the right angled triangle. Pythagorus Theorem relates the sides of the right angled triangle and not relating all the sides of the other similar triangles, by equating the square of the hypotenuse to the sum of the squares of the other two sides of a right angled triangle. The hypotenuse is nothing but the side opposite to the right angle and it is related to the other 2 legs of the right angled triangle by this Pythagorus Theorem. So the given statement about the triangles is False.