Final answer:
The assertions that there are two types of interference (constructive and destructive) and that the Pythagorean theorem can be used to calculate the magnitude of a resultant vector at right angles are both true. The alignment of waves is only significant for constructive interference.
Step-by-step explanation:
Understanding Interference and the Pythagorean Theorem in Physics
The answer to the question 'Is the following statement true or false? The two types of interference are constructive and destructive interferences.' is true. In physics, constructive interference occurs when two waves are in phase and their amplitudes enhance each other, while destructive interference happens when two waves are out of phase and their amplitudes weaken each other.
In regards to the statement 'The amplitude of one wave is affected by the amplitude of another wave only when they are precisely aligned.', this is true in the context of constructive interference, where alignment (being in phase) is critical for the waves to constructively interfere.
As for the question concerning the Pythagorean theorem, 'Can we use Pythagorean theorem to calculate the length of the resultant vector obtained from the addition of two vectors which are at right angles to each other?' the answer is true. The Pythagorean theorem is applied in physics to determine the magnitude of the resultant vector when two vectors are perpendicular to each other.