Question

A tree casts a shadow 12 meters long. At the same time, a building 60 meters tall casts a shadow 36 meters long. How tall is the tree? 60 m 12 m 36 m A 180 meters B 21 meters C 20 meters D 19 meters?

Answer 1

The triangles are similar using that the light from the sun forms the same angle with every object. Then the triangles are similar, and their sides are proportional. If h is the height of the tree then we have

$\begin{gathered} \frac{h}{12}=\frac{60}{36} \\ h=\frac{60\times12}{36} \\ h=20 \end{gathered}$

So, the height of the tree is 20 m