The image can be drawn as,
The height of the person can be determined as,
[tex]\begin{gathered} \tan C=\frac{AB}{CB}=\frac{DE}{CE} \\ \frac{AB}{CB}=\frac{DE}{CE} \\ \frac{15}{20}=\frac{DE}{8} \\ DE=\frac{15\times8}{20} \\ DE=6\text{ ft} \end{gathered}[/tex]Thus, the required height of the man is 6 ft.
