Check my math - Page 2

# Thread: Check my math

1. ## Re: Check my math

Originally Posted by Squarepeg
Willie,
If your phone gives you the angle from level in degrees, try this. If the angle is 17 degrees, enter 17 into a calculator then press TAN. Tan is "opposite over adjacent", but forget about that. Sounds like 11th grade trig class (I didn't like it much but took it twice anyway). Tan is really Rise over Run. This I can get my head around. Ok, 17 Enter, TAN, =.3057..., x 100= 30.57. So, 17 degrees drops or rises about 30 1/2 ft along 100 ft. Three strokes on a calculator.
Just a small note: rise over run is only correct when the right triangle is drawn with one leg as the ground and using the acute angle near the ground.

Using the acute angle at the top, rise over run would be incorrect.

If the triangle is drawn with the hypotenuse as the "ground" it would also be incorrect.

Regardless of right triangle orientation, opposite over adjacent is always correct.

Also, some phones use the other method of entry where tan(17) would be typed as it is normally written.

It's usually the difference between BASIC operation and AES.
https://en.wikipedia.org/wiki/Calcul...ix_notation.29
Last edited by MinnesotaDave; 12-08-2017 at 03:13 PM.

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