Question

if a tree cast a 28 foot shadow and a man who is 7 feet cast an 2 foot shadow how tall is the tree.

Answer 1

We can draw this problem as:

Then, we can relate the proportions height/shadow for the man and the tree. As they form corresponding triangles, the proportions must be equal:

$\begin{gathered} \frac{\text{height}}{\text{shadow}}=\frac{x}{28}=\frac{7}{2} \\ x=\frac{7}{2}\cdot28 \\ x=\frac{196}{2} \\ x=98 \end{gathered}$

Answer: the height of the tree is 98 ft.