Answer:
4² + 5² = x²
Step-by-step explanation:
From the picture, the height of the staircase is:
h = 20 ft -15 ft = 5 ft
And the distance between the staircase and the building is 4 ft.
A right triangle is formed, where the distance between the staircase and the building (4) and the height of the staircase (5) are the legs, and the length of the staircase (x) is the hypotenuse. Using Pythagorean theorem:
4² + 5² = x²