In this Instructable, I will show you how to make a basic clinometer from classroom materials. A simple version of surveying equipment, a clinometer can be used to find the angle you are looking, for instance from where you are standing to the top of a tree. Combined with the distance to the base of the tree (and a little bit of trigonometry), this can be used to calculate the height of the tree. Click here
to see how to use this clinometer to find the height of a tall object.