Question 1013227
Okay, sure...
Make yourself a diagram...the angle of depression from the plane is equal to the angle of elevation from the base of the tree...call it x...
We need to find the distance to the tree along the ground from under where the plane is...
We can use the tangent...50' of arc is .833 degrees
tan 13.833 degrees = 10500 / x
or
x = 10500 / tan 13.8333 = 42641 feet