Using a Clinometer on Elephant Island
Trying to estimate the height of a peak on Elephant Island? Use a clinometer by following these simple steps:

Assemble. Use the clinometer you received in the mail (or download and assemble a clinometer here). Now it’s time to practice!

Target. Go outside and find a tall object you’d like to measure, such as the top of a nearby tree, phone pole, building, etc. Make sure you’re in a safe area with parent supervision! Put a mark on the ground where you’ll be standing.

Measure. You’ll need to write down the following measurements (try to take all measurements using the metric system, i.e., cm, m, mm, etc.):

1) Distance from your mark to the base of the object. Hint: if you measure your shoes, you can then count how many shoe lengths it takes to get from your mark to the base, then multiply.

2) The angle necessary to view the top of the object. Position yourself on your mark, and stand up straight. Hold the clinometer up to your eye, and look through the straw until you’re only seeing the top of the object. The dangling string will indicate the angle you need.

3) The height of your eyeballs. It sounds funny, but how high are your eyes off the ground? You might ask a parent to help you measure.


Calculate. Now find the height by using the following calculations:

1) Subtract your measured angle from 90 degrees (this is necessary since we’re using the protractor upsidedown).

2) Find the “tangent” of your angle. Sound complicated? Just use this calculator. Use “trigonometric functions,” adjust the first dropdown option so it says “tan,” and make the second dropdown option show “°” for degrees. Now type in your angle and select “calculate.”

3) Multiply the tangent by the distance from your mark to the base of your object. That’s how high the object is from your eyelevel! Add in the height of your eyeballs, and you’ve got the answer.


Solve. Once you’ve practiced on a few reallife objects, find the missing story problem on Elephant Island and use the same methodology to measure the height of the peak. Your answer will be a whole number (in meters). Good luck!