Question

A child who is 4 feet tall casts a 6-foot shadow at the same time that a nearby tree casts a 30-foot shadow. What is the height, in feet, of the tree?

Answer 1

As the triangles that form the tree and the child are congruent we have that

$\begin{gathered} \frac{x}{4}=\frac{30}{6}=5 \\ x=5\cdot4=20 \end{gathered}$

so the tree is 20 feet tall