This is a hands-on activity I have my students do after introducing right triangle trigonometry (SOH CAH TOA). As motivation we discuss applications of trig such as forestry! I have a set of clinometers and 15 meter measuring tapes, but students can actually make their own clinometers with string and protractors! We do the two examples together in class, and then I have student practice using the clinometers. Then, they can go outside and take measurements of trees, buildings, flag poles, etc.