Answer: D. 122
Step-by-step explanation: The given polygon is a right triangle, and to calculate any length of any side in a triangle we use Pythagorean Theorem. According to Pythagorean Theorem, the right triangle consists of one hypotenuse that is opposite to the right angle and two other sides that lie at an right angle. From this comes the relationship that always applies to the right triangles, that the area of the square located on the hypotenuse is equal to the sum of the areas of the squares that are located on the other two sides.
Pythagorean Theorem can also be expressed using the equation:
a² + b² = c²
where c is the hypotenuse and a and b are the other two sides of the right triangle.
According to the given triangle, the length of the BC side is the length of the hypotenuse we are looking for, while the lengths of the sides a and b are given, a = 22 and b = 120.
Using Pythagorean Theorem, hypotenuse BC is equal to
c² = a² + b² = 22² + 120² ⇒ c = √(22² + 120²) = √(484 + 14400) = √14884
c = 122