Brian
One use of Trig is to calculate the height of tall objects, such as a tree or flagpole. You may wonder how tall the object is but have no way to reach the top to measure the height.
Instead, you can use trigonometry to calculate the height:
- Stand some distance away from the object and measure your distance to it.
- Then use a protractor to estimate the angle formed between the line parallel to the ground at your eye level and the line from your eyes to the top of the object.
- Use your calculator to find the tangent of the angle from step 2. For example, if the angle was 35 degrees, you would get approx. 0.700.
- Multiply your distance from the object by the result from step 3. For example, if you were 20 feet from the object, you would multiple 20 by 0.7000 to get about 14 feet. So the object is approximately 14 feet tall.
Note: Sohcahtoa is an easy way to remember how sine, cosine, and tangent work:
Soh: sine = opposite / hypotenuse
cah: cosine = adjacent / hypotenuse
toa: tangent = opposite / adjacent
