Hello, everyone.
This is Enta.
I'm writing this blog in an easy-to-understand way to teach my employees, but,
Since some posts are on Ameblo but not here, I usually repost the ones I use frequently.
For now, reading the text to get a general idea and then checking it on-site will help you gain an even deeper understanding.
But teaching people things is really hard, isn't it?
But that's beside the point.
This time, we'll be discussing right angles on slopes.
Well, it's a simple matter, but I'll explain the calculation method for drilling holes perpendicular to the slope.
A slope of 1:0.3 corresponds to an angle of 73 degrees.3-minute gradient
A slope of 1:0.4 corresponds to an angle of 68 degrees.4-minute gradient
A slope of 1:0.5 corresponds to an angle of 63 degrees.5-minute gradient
A slope of 1:0.6 corresponds to an angle of 59 degrees.6-minute gradient
A slope of 1:1.0 corresponds to an angle of 45 degrees.10% gradient
When the slope angle is like this,The perpendicular direction was subtracted from 90 degrees
The angle perpendicular to a slope of 1:0.3 is 17 degrees.
The angle perpendicular to a slope of 1:0.4 is 22 degrees.
The angle perpendicular to a slope of 1:0.5 is 27 degrees.
The angle perpendicular to a slope of 1:0.6 is 31 degrees.
The angle perpendicular to a slope of 1:1.0 is 45 degrees.
If you calculate this on a calculator, you'll get this result↓↓
tan-1(1÷0.3) = 73.3 degrees
tan-1(1÷0.4) = 68.2 degrees
tan-1(1÷0.5) = 63.4 degrees
tan-1(1÷0.6) = 59.0 degrees
tan-1(1÷1.0) = 45.0 degrees
When I use a calculator, I get a decimal. If I round this off or truncate it,↑↑It will be the same number.
First, (1 ÷ 0.3) = 3.3333…; the answer is the same when expressed as tan⁻¹ (arc tangent).
And,Right angleSo,
The angle formed by subtracting a number from 90 degrees is the right angle relative to the slope.That's how it works.
A 3-minute gradient and a right angle of 73.3 degrees result in 90 degrees – 73.3 degrees = 16.7 degrees.
A 4-minute gradient and a right angle of 68.2 degrees result in 90 degrees – 68.2 degrees = 21.8 degrees.
For a 5-minute gradient, the right angle of 63.4 degrees is 90 degrees – 63.4 degrees = 26.6 degrees.
A 6-minute gradient and a right angle of 59.0 degrees result in 90 degrees – 59.0 degrees = 31.0 degrees
A 10% slope; the right angle of 45.0 degrees is 90 degrees – 45.0 degrees = 45.0 degrees
That's how it works.
I'm sure there are other ways to calculate this, but this method works too.
It’s really no big deal once you get the hang of it, but I’m actually embarrassed to think that I used to draw things in CAD and measure the angles myself before I figured it out lol.
Please follow the design specifications regarding decimal places. If you round them off on your own, you'll get in trouble, lol.
See you later.
When Installing Rebar, Should It Be Perpendicular to the Slope or at a Specified Angle!? (Part 1)
