What is a expression equivalent to ^3√8x^2y^3z^4

3sqrt(8x^2y^3z^4)
=2sqrt(8)xy^(3/2)z
=4sqrt(2)xzy^(3/2)
hope it helps :)

This is right triangle trig and you are looking for the height of the triangle. The reference angle is 18 degrees, the side adjacent to that angle is 4 and you are looking for the side opposite the reference angle.  The trig identity that helps us find that missing side is tangent:

and 4 tan(18) = x.
x = 1.3 miles