# Trigonometry

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Perhaps some of my fellow shade-tree machinists would have a use for my easy way to figure the three most common angles.

First you need a scientific calculator, such as a Texas Instruments TI-30, which costs approximately \$11. Then you substitute your known numbers and angles for the ones in the three problems (see examples). Keep in mind that with angles, the numbers represent degrees, minutes and seconds, in that order.

To Find A

Use the numbers to the left of the decimals point for your angle.
8. 49           (Degrees)
29.4            (Minutes)
24.0            (Seconds)

Use the numbers to the right of the decimal point to figure the problem.
8.49
29.4
24.0

To Find A
Punch 0.224
Punch
Punch 1.500
Punch = 0.149
Punch INV
Punch TAN = 8.49
Punch 0.49
Punch x
Punch 60
Punch = 29.4
Punch 0.4
Punch x
Punch 60
Punch = 24
A = 8°, 29°, 24'

To Find B and C

Follow my format and you should have no trouble.

The tricky part of B and C is if your angle is 15°22'.

Let's do B
Divide 22 into 60
Punch 22
Punch
Punch 60
Punch =

To Find B
Punch 1.312
Punch
Punch 15
Punch SIN
Punch = 5.069

B = 5.069

To Find C
Punch .500
Punch x
Punch 7
Punch TAN
Punch = 0.061

C = 0.061

You will get 0.3666667. Use 36 so your angle would read 15°36' and then figure B. In other words, if your known angle is 15°36', you would punch in 15.36.

Try it and you will see how easy trig can be.

Contact Pete Fisher at 4722 West 45th Avenue, Gary IN 46408