Question

In the diagram, a building casts a 20-ft shadow and a flagpole casts a 7-ft shadow. If the flagpole is 12 ft tall, how high is the building? Round to the nearest tenth. .

Answer 1

Answer:

Height of Building is 34.3 ft

Step-by-step explanation:

Given Length of shadow of  building = 20 ft

Length of shadow of flagpost     = 7 ft

Height of flagpole = 12 ft

Let, height of building is x

This problem is of Direct proportion,

As when if height of object increases then length of shadow also increases at same time.

We use the result,

$\frac{x_1}{x_2}=\frac{y_1}{y_2}$

$\frac{x}{20}=\frac{12}{7}$

$x=\frac{12}{7}\times20$

$x=\frac{240}{7}$

$x=34.2857143$

$x=34.3$

therefore, Height of Building is 34.3 ft

Answer 2

12/7 = x/20 
7x = 240 
x = 34.3 ft