Math problem

[cprowell]

We are building a fence on a sloped grade. There is a trigonometric function that will give us the angle to cut the horizontal rails. Does anyone know the answer?

A level length of 113". A rise of 6". We can find the hypotenuse by 113 squared + 6 squared equals the hypotenuse squared. But what is the angle?

Sketch attached.

Thanks

[Chris Murray]

I think the answer is 87 degrees, being 90 - arctan(6/113).
More here:
https://www.mathwarehouse.com/trigonometry-calculators/inverse-tangent-calculator-online.php

(https://www.mathwarehouse.com/trigonometry-calculators/inverse-tangent-calculator-online.php)

[spam1]

correct answer to the question, but if you use a chop saw to cut the board, you might have to set it to 3 degrees (which is 3 degrees offset of a square (or 90 degree) cut. Yes, I know, obvious once you put the board on a chop saw.


I think the answer is 87 degrees, being 90 - arctan(6/113).
More here:
https://www.mathwarehouse.com/trigonometry-calculators/inverse-tangent-calculator-online.php

(https://www.mathwarehouse.com/trigonometry-calculators/inverse-tangent-calculator-online.php)

[cprowell]

Thank you. 87-degrees, or a 3-degree cut on the chop saw. I appreciate the replies.