Look through the free end of the tube, opposite the protractor, or sight along the tube’s top edge.
Focus on something at eye level. Ask your partner to read the angle where the string crosses the protractor. If your inclinometer is level, the string should cross the protractor at about 0 degrees.
If you’re trying this without a partner, look through the tube and pinch the string against the card to hold it in place. Then take the tube away from your eye and read the angle on the protractor. (Be careful not to move the string and change the angle!) Try this a few times, until you get the hang of it.
Now look through the tube at the top of something tall. If you’re indoors, look at something near the ceiling and find the angle where the string crosses the protractor. What do you think will happen if you change the distance between where you’re standing and the tall object you’re sighting? Make a guess, then take a few steps toward or away from the object and check your inclinometer. What happened to the angle?
Use your inclinometer to measure the top of something tall, but not too far away. Determine the angle on your inclinometer and write it down. This is the angular height of the object.
Use your measuring tape to find out how far the base of that object is (in centimeters) from where you’re standing. Write down this distance.
Have a partner measure how far it is from the floor to your eye level. Write down this distance.
You now have all the data you need to find the height of the object. You could use trigonometry to find the answer, but we’ve provided a handy Height Calculator Grid that will also do the job.
To begin, use a ruler to draw a line from the angle you measured through the origin and across the grid (see example in photo below).
Find the distance to your object along the horizontal (x) axis. Now note the scale of the grid. Draw a vertical line through that distance across the grid, and then find the place where the two lines intersect. Read the height along the vertical (y) axis. Notice the scale of the grid as you determine this height.
Notice that the x axis is labeled “eye level” because your measurement was taken from that height. To account for that measurement, add the height from the grid to the distance from your eye to the ground. This is the height of your object.