Question

On a sunny day, a person who is 5 feet tall casts a 3 feet long shadow. Find the height of a nearby flagpole which casts a 12 feet long shadow.

• A. 10 feet
• B. 15 feet
• C. 25 feet
• D. 20 feet

Answer 1

The correct option is D

20 feet

We can see that , $△ABC\sim △DEF$ by AAA Similarity Criterion

$\Rightarrow \frac{AB}{DE}=\frac{BC}{EF}$

$\Rightarrow \frac{AB}{5}=\frac{12}{3}$

Thus, AB = 20 feet