Question

In the diagram, a building casts a 21-ft shadow and a flagpole casts a 6-ft shadow. If the flagpole is 15 ft tall, how high is the building? Round to the nearest tenth.

Answer 1

Ratio Problem

15 tall Flagpole     6 shadow Flagpole
-------------------- = -------------------------
      x tall build        21 shadow build

6x = 315
x = 52.5

Answer 2

Answer:

52.5 ft high is the building

Step-by-step explanation:

Proportion states that two ratios or fractions are equal

As per the statement:

In the diagram,

a building casts a 21-ft shadow and a flagpole casts a 6-ft shadow.

If the flagpole is 15 ft tall.

Let x ft be the height of the building.

then by definition we have;

$\frac{\text{Height of the building}}{\text{Shadow of the building}}=\frac{\text{Height of the flagpole}}{\text{Shadow of the flagpole}}$

$\frac{x}{21} = \frac{15}{6}$

By cross multiply we have;

$6x = 315$

Divide both sides by 6 we have;

$x = 52.5$ ft

Therefore, 52.5 ft high is the building