How to Use Trigonometry in Carpentry

Its a simple fact that many of us had hoped to leave the lessons of trigonometry far behind us after high school. However, if you've begin a career in carpentry, those skills will come in handy after all. Each time a carpenter makes an angled cut, the exact measurement of those angled lines needs to be figured out: this is called trigonometry.

What You'll Need:

• Measuring tape
• Square
• Notepad
• Pencil
• Calculator

1. Familiarize yourself with the basic function for a right triangle: Sine of angle = Opposite/hypotenuse Cosine of angle = Adjacent/hypotenuse Tanget of angle = Opposite/adjacent.
2. Figure that you are cutting a support board to be used as a table mounted up against a wall and you want the support to sit at at 35-degree angle. You'll need to find out what the resulting height of the bench is if the bench is 48 inches wide. In order to determine this you would use the following equation: Tan 35-degrees = Opposite/48 inches x tan 35-degrees = Opposite 48 inches x 0.70 = OppositeOpposite = 33.5 inches.
3. Establish the length of the hypotenuse or support. Use the Pythagorean theorem: a^2 + b^2 = c^248^2 + 33.5^2 = c^2c^2 = 3426.25c = 58.5 inches.
   
4. Decide the measurement of the final angle. So if you know the angles add up to 180-degrees then you'd use the following equation: 90-degrees + 35-degrees = 180-degrees - unknown125-degrees = 180-degrees - unknownunkown = 55-degrees.
5. Ensure that you document all of your measurements by keeping them in a notebook. Completing this step will expedite the process the next time you need to take the same measurement.