Consider the height of oak tree be x.
Determine the relation between oak tree height and distance B by using trigonometric ratio.

Determine the relation between height of kite and distance B using the trigonometric ratios.

The difference between height of kite (a) and height of oak tree (x) is 35 ft or,

Substitute vaue a and x from the obtained to obtain the equation in terms of b.

The distance for the Macros standing from foot of tree is 195 ft.