Question

A telephone pole casts a shadow that is 50 feet long. Nearby, an 8-foot tall traffic sign casts a shadow that is 10 feet long. How tall is the telephone pole?

Short answer

The telephone poll s 40 feet long.

Step-by-step solution

Given information

The telephone pole that casts the shadow 50 feet along with the 8-feet long traffic signal casts the shadow 10 feet.

Find the length of the poll

Apply the proportions to find the length of the poll.

• As given, the proportion for the poll and the traffic signal with respect to the shadow is the same.
• Hence solve equation (1) to find the value of h that represents the length of the poll.

$\begin{array}{rcl}\frac{h}{50}& =& \frac{8}{10}...............\left(1\right)\\ h& =& \frac{8}{10}\times 50\\ & =& 8\times 5\\ & =& 40feet\end{array}$