Question 89898
Draw a picture of a right-triangle.
1800 feet is the height of the triangle, meaning from the top of mountain to where Tom stop.
3.25 mile is the slant of the triangle.
So what you can imagine is that Tom is coming down the slant.  When travelled 3.25 miles from the top, he's decended 1800 ft.
********* Step #1: Use {{{a^2 + b^2 = c^2 }}} to find all sides of the triangle
Where a=1800 ft and c=3.25 miles.
(Note: 1 miles = 5280 feet; so 3.25 miles is 17160 ft.)
{{{a^2 + b^2 = c^2 }}}
becomes {{{1800^2 + b^2 = 17160^2 }}}
becomes {{{b = 17065 ft }}}
********* Step #2: Solving slope of decent
slope = Rise/Run.
In this case our Rise=1800; Run=17065
becomes {{{slope = -1800/17065 = -0.11 }}}