Question

How tall is the goal post if its shadow is 18ft. The height of the flagpole is 20 ft and its shadow is 8 ft.?

Answer 1

You can set up an inequality to solve this. You can either do big to small --> $\frac{x}{18} = \frac{20}{8}$ or small to big --> $\frac{x}{18} = \frac{8}{20}$. I'm going to be using big to small because I think it's a little easier.

$\frac{20}{8} = \frac{x}{18}$

Cross multiply and you will get:

$360 = 8x$

Isolate x:

$x = \frac{360}{8}$

x = $\frac{90}{2}$

x = 45

The goal post is 45 feet tall. Hope this helped. Good luck. : )