What is the hypotenuse in a right triangle?

In a right triangle, the hypotenuse is defined as the side opposite the right angle and is also the longest side of the triangle. This characteristic arises from the Pythagorean theorem, which states that in a right triangle, the square of the length of the hypotenuse (c) is equal to the sum of the squares of the lengths of the other two sides (a and b). This relationship inherently makes the hypotenuse the longest side in any right triangle configuration.

Understanding the role of the hypotenuse is essential for solving various problems involving right triangles, such as determining distances and angles using trigonometric functions. The identification of the hypotenuse as the longest side establishes a foundational concept in geometry and trigonometry. Consequently, the correct choice reflects this fundamental attribute of the hypotenuse in a right triangle.