Final answer:
The statement that the Pythagorean theorem can be used to calculate the length of a resultant vector from two vectors at right angles is true.
Step-by-step explanation:
The Pythagorean theorem is a mathematical principle that applies to right-angled triangles and is used to determine the length of the sides of such triangles. It states that in a right-angled triangle, the square of the length of the hypotenuse (the side opposite the right angle) is equal to the sum of the squares of the lengths of the other two sides. This principle can indeed be applied to vectors as well, specifically when calculating the magnitude (or length) of a resultant vector that is obtained from the addition of two vectors that are perpendicular to each other.
In response to the given statement, 'True or False-We can use the 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. When adding two vectors that form a right angle, the resultant vector forms the hypotenuse of a right-angled triangle, and its length can be found using the Pythagorean theorem, where if 'a' and 'b' are the magnitudes of the two original vectors, the magnitude of the resultant vector 'r' would be calculated as '√(a²+b²)'.