A triangle is formed by the building's height and shadow. Another triangle is formed by the flagpole's height and shadow. Using the following diagram, find the height of the building. 1 20 ft 30 ft 3 ft The height of the building is feet.

x ≈ 2.76, x ≈ 7.24

Step-by-step explanation:

Given

x² - 10x + 20 = 0 ( subtract 20 from both sides )

x² - 10x = - 20

To complete the square

add ( half the coefficient of the x- term )² to both sides

x² + 2( - 5)x + 25 = - 20 + 25

(x - 5)² = 5 ( take the square root of both sides )

x - 5 = ± ( add 5 to both sides )

x = 5 ±

Hence

x = 5 - ≈ 2.76

x = 5 + ≈ 7.24