Question

Julia is standing 2 feet away from a lamppost. If she casts a shadow of 5 feet and the light makes a 20° angle relative to the ground from the top of her shadow, how tall is the lamppost?

Answer 1

Answer:

2.5477 feet

Step-by-step explanation:

Refer the image attached to understand my solution.

BC = height of lamppost.

DE = Julia

AD = shadow of Julia

BD = 2 feet.      AD = 5 feet

BA = BD + AD

       = 2 + 5 = 7 feet

In ΔABC

tan 20° = $\frac{BC}{BA} = \frac{BC}{7}$

BC = 7 * tan 20°

BC = 2.5477 feet

SO the height of lamppost = 2.5477 feet