Final answer:
The lengths are arranged in a way that suggests the possible use of the Pythagorean theorem, which is applicable to right-angled triangles. The correct answer is D. 13 feet.
Step-by-step explanation:
To determine the length of the ladder, we can use the Pythagorean theorem, which states that in a right-angled triangle, the square of the length of the hypotenuse (the ladder) is equal to the sum of the squares of the lengths of the other two sides. In this case, the ladder forms a right-angled triangle with sides of 5 feet and 12 feet.
Let's denote the length of the ladder as 'L.' According to the Pythagorean theorem:
L² = 5² + 12²
L² = 25 + 144
L² = 169
Taking the square root of both sides:
L = √169
L = 13
Therefore, the length of the ladder is D. 13 feet.