The answers are provided to the document, Trigonometry Application: Clinometer Activity also posted on this Math Matters MM site.
The activity is a math lab, where students measure distances and angles of various items and use a clinometer to determine the height of the objects. The school soccer net, flagpole and building are used, but any tall object will also work. Percent error is calculated also. All instructions on building the clinometer are included and sample calculations are included in this answer document.