Question

A flagpole is next to a building as shown in the drawing below. The flagpole is 30 feet tall and casts a shadowof 120 inches. The building casts a shadow 648 inches longHow tall is the building in feet?

Answer 1

The triangle formed by the flagpole and its shadow is similar to the triangle formed by the building and its shadow. In similar triangles the ratio between corresponding sides is the same.

`\frac{\text{Flagpole}}{x}=(Building)/(y)`

Use the given lengths and in the equation above and find the height of the building:

`\begin{gathered} (30ft)/(120in)=\frac{\text{Building}}{648in} \\ \\ \text{Building}=648in\cdot(30ft)/(120in) \\ \\ \text{Building}=162ft \end{gathered}`

Then, the building is 162 feet tall