Clinometer: Making a Clinometer with in-school Supplies

If you build it, it will work.  Build a clineometer from the supplies around you in the class room.  You can construct a simple and easy way to measure angles of elevation to use with many geometric and trigonometric applications.  Those measurement can then be used to find the height of any object.

Engaging Questions

  • How would you meaure the height of tall objects like Chicago's Sears Tower, New York's Statue of Liberty, or Seattle's Space Needle if you never left the ground?

Teacher Goals

  • Students will construct a clineometer using a protractor, tape, string and a weighted object

  • Students will interpret the angle of elevation from the clineometer by using complimentary angles

  • Students will claculate the height of several objects by using the clineometer and angle of elevation

Required Resources

  • Plastic protractor showing degree measure

    Found at any local store offering school supplies. You can substitute a photo copy glued to a firm piece of cardboard.

  • Tape

    4 inches of scotch tape

  • Plastic straw

    Is not a must but will help with maintaining some accuracy.

  • String

    6 inches of string. You can substitute yarn, nylon, etc.

  • Weighted Object

    Any small object carry some amount of weight. Example: several paper clips, a key, a pencil, tacky, etc.

  • Scientific calculator

    Scientific calculator that contains the function keys "sin", "cos", and "tan".

Optional Resources

  • Paper and Pencil

Steps

  1. Attach String

    Locate the cross-hairs, the bubble, the notch, or the hole on the hozizontal line.  It will be found in the middle of the horizontal line.  Tape the string to the protractor at that spot.  Place tape on the horizontal edge side.  The string should hang down as the protractor is held upside down.  Make sure the string can swivel as the protractor is tilted up and down.

  2. Attach straw

    Tape the straw along the horizontal black line found at the bottom portion of the protractor.  Some protractors do not have this line and they use the bottom edge as their horizontal line.  The straw will run the length of the protractor

  3. Attach weight

    Tie your wieghted object to the end of the string.  The string and the weight should hang past the rounded edge of the protractor as you hold it upside down.

  4. Interpreting the angle measure

    Your clinemoeter measures the complimentary angle of elevation of the object you are viewing.  Hold the protactor upside down with the straw on top.  Hold the protractor to your eye.  Look through the straw towards you object.  Determine the angle indicated by the string and the protractor.  **Special Note**  This angle will always be between 0 and 90 degrees.

  5. Finding the angle of elevation

    Take the complementary angle as indicated on your clineometer and subtract it from 90 degrees.  This is your angle of elevation you are trying to measure.

  6. Distance from the Object

    Using a measuring tape, measure the distance from the base of the object to the point at which you are standing as you measure the angle of elevation.

  7. Calculate the Height

    Calculate the height of the object by using your calculator and the attached collection sheet.

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