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.

Step 1: Materials

To make this clinometer, start by gathering the following materials:

- 1 Protractor
- 1 Piece of thin string, fishing wire, or strong thread, approximately 10" long
- 1 Drinking straw
- Weight that can be tied to the string (I used a large binder clip)
- Transparent tape

Step 2: Attach String to Protractor

Slide approximately one inch of the string through the hole at the center of the protractor, and use tape to secure it.

Step 3: Attach Weight

Attach your weight to the other end of the string. I used a large binder clip because that's what I had on hand, but anything that can be easily tied to the string will work (a few heavy washers would work well). This weight will keep the string taught and enable you to read the angle while you are using the clinometer.

Step 4: Attach Straw

Attach the straw along the straight edge of the protractor using tape. You will look down through this straw to aim your clinometer at what you are measuring.

Congratulations, you're done! Check out my other Instructable on how to use this clinometer to measure the height of something tall.