This is a problem of similar triangles, then let's make a sketch of the situation:
Then, those triangles are similar, then if we call x the height of the tree, the theorem of similar triangles states:
[tex]\frac{x}{5ft7in}=\frac{20ft}{5ft}[/tex]First let's convert 5ft7in to feet:
[tex]\begin{gathered} \frac{1ft}{12in}=\frac{x}{7in} \\ x=\frac{7}{12}=0.58ft \\ \text{Then 5ft7in=5.58ft} \end{gathered}[/tex]Now, let's solve for x:
[tex]\begin{gathered} \frac{x}{5.58ft}=\frac{20ft}{5ft} \\ x=\frac{20\times5.58}{5} \\ x=\frac{111.7}{5} \\ x=22.33\approx22ft \end{gathered}[/tex]Then the height of the tree is 22 ft