Given data:
The height at the top is H= 210 ft.
The height at the bottom is h= 15 ft.
The expression for the change in the height is,
[tex]\begin{gathered} d=H-h \\ =210\text{ ft -15 ft} \\ =195\text{ ft} \end{gathered}[/tex]Thus, the change in the height is 195 ft.