# For math experts

Discussion in 'Computer Support' started by John Smith, Nov 30, 2003.

1. ### John SmithGuest

I have no access to a proper protractor to do this with so I need to know what
the measurements are in cutting an angle.
Assume we have at our disposal a standard 2x4 and wish to cut a 60 degree angle.

What would the measurement be from the right side of the edge to the left most
edge of the triangle?
Assuming the top right edge is one corner, and the lower right edge is another
corner.

Or if you have a 60 degree fixed angle guide handy, measure each side and let me
know what they are. Thanks.

John Smith, Nov 30, 2003

John Smith <> Ran in the back door and shouted
news::

> I have no access to a proper protractor to do this with so I need to
> know what the measurements are in cutting an angle.
> Assume we have at our disposal a standard 2x4 and wish to cut a 60
> degree angle.
>
> What would the measurement be from the right side of the edge to the
> left most edge of the triangle?
> Assuming the top right edge is one corner, and the lower right edge is
> another corner.
>
> Or if you have a 60 degree fixed angle guide handy, measure each side
> and let me know what they are. Thanks.
>
>

Ever hear of using cardboard as a template?
Even a piece of paper will do....

--

John Smith said:

> I have no access to a proper protractor to do this with so I need to know what
> the measurements are in cutting an angle.
> Assume we have at our disposal a standard 2x4 and wish to cut a 60 degree
> angle.
>
> What would the measurement be from the right side of the edge to the left most
> edge of the triangle?
> Assuming the top right edge is one corner, and the lower right edge is another
> corner.
>
> Or if you have a 60 degree fixed angle guide handy, measure each side and let
> me know what they are. Thanks.

Draw a line between the 2 points, divide it into 10 equal lengths, cut at the
6th division.

> John Smith said:
>
>> I have no access to a proper protractor to do this with so I need to know
>> what the measurements are in cutting an angle.
>> Assume we have at our disposal a standard 2x4 and wish to cut a 60 degree
>> angle.
>>
>> What would the measurement be from the right side of the edge to the left
>> most edge of the triangle?
>> Assuming the top right edge is one corner, and the lower right edge is
>> another corner.
>>
>> Or if you have a 60 degree fixed angle guide handy, measure each side and let
>> me know what they are. Thanks.

>
> Draw a line between the 2 points, divide it into 10 equal lengths, cut at the
> 6th division.

Oops, before you get your saw out, redraw with 9 divisions, not 10.

John Smith wrote:

> I have no access to a proper protractor to do this with so I need to know what
> the measurements are in cutting an angle.
> Assume we have at our disposal a standard 2x4 and wish to cut a 60 degree angle.

Got a graphics program? Some/most of the good ones will, when you draw
a line, tell you its angle. Draw one that shows as 60 degrees. Print
it. Transfer it to your stock.

--
Blinky - - - - - - - - - - - - - - - - - - - - - - - Linux RU 297263
[still no new sig]

Blinky the Shark, Nov 30, 2003
6. ### RichardGuest

> John Smith wrote:

>> I have no access to a proper protractor to do this with so I need to
>> know what the measurements are in cutting an angle. Assume we have at
>>our disposal a standard 2x4 and wish to cut a 60 degree angle.

> Got a graphics program? Some/most of the good ones will, when you draw
> a line, tell you its angle. Draw one that shows as 60 degrees. Print
> it. Transfer it to your stock.

Good idea. But what if you're out in the field and have only a hand saw, a
ruler, and a pencil?
Knowing that the height of the triangle is going to be 4 inches, what is the
length of the base of the triangle?
If the base length is also 4 inches, we know that will give us a 45 degree
cut right?
So to get 60 degrees, the base line length would be shorter yes?
So what's the length needing to be?

> --
> Blinky - - - - - - - - - - - - - - - - - - - - - - - Linux RU 297263
> [still no new sig]

Richard, Nov 30, 2003
7. ### -= Hawk =-Guest

On Sun, 30 Nov 2003 02:02:29 -0600, "Richard" <anonymous@127.000>
scribbled:

> But what if you're

The subject says 'for math experts', it makes no mention
of moronic, unemployed pedophiles.

--
'What Profiteth It A Kingdom If The Oxen Be Deflated?'
Riddles II, v3
- T. Pratchett

-= Hawk =-, Nov 30, 2003

Richard wrote:

> > John Smith wrote:

> >> I have no access to a proper protractor to do this with so I need to
> >> know what the measurements are in cutting an angle. Assume we have at
> >>our disposal a standard 2x4 and wish to cut a 60 degree angle.

> > Got a graphics program? Some/most of the good ones will, when you draw
> > a line, tell you its angle. Draw one that shows as 60 degrees. Print
> > it. Transfer it to your stock.

> Good idea. But what if you're out in the field and have only a hand saw, a
> ruler, and a pencil?

I'd be screwed.

> Knowing that the height of the triangle is going to be 4 inches, what is the
> length of the base of the triangle?

For starters, a 2x4 isn't 2" x 4", so you're already in trouble if you're going
to use a math approach, as you'll be starting from an incorrect dimension.

> If the base length is also 4 inches, we know that will give us a 45 degree
> cut right?

Yes, with base and alt the same -- not that those even-inch dimensions apply to
a 2x4.

> So to get 60 degrees, the base line length would be shorter yes?

Or longer, depending on which vertex you wanted to be 60 degrees.

> So what's the length needing to be?

Dunno. Your limitations of what I have on hand don't include trig tables.

I'll trade you that ruler for a compass. Don't need the ruler; could do this
with the compass.

--
Blinky - - - - - - - - - - - - - - - - - - - - - - - Linux RU 297263
[still no new sig]

Blinky the Shark, Nov 30, 2003
9. ### CiceroGuest

"John Smith" <> wrote in message
news:...
> I have no access to a proper protractor to do this with so I need to know

what
> the measurements are in cutting an angle.
> Assume we have at our disposal a standard 2x4 and wish to cut a 60 degree

angle.
>
> What would the measurement be from the right side of the edge to the left

most
> edge of the triangle?
> Assuming the top right edge is one corner, and the lower right edge is

another
> corner.
>
> Or if you have a 60 degree fixed angle guide handy, measure each side and

let me
> know what they are. Thanks.
>

===========
On most ordinary wood saws you'll find that the front part of the handle
is designed with both 90 degree and a 60 degree angles built in.

Cic.

Cicero, Nov 30, 2003
10. ### -= Hawk =-Guest

On 30 Nov 2003 08:53:19 GMT, Blinky the Shark <>
scribbled:

> you'll be starting from an incorrect dimension.

RtS started from a dimension of extreme stupidity.

--
'What Profiteth It A Kingdom If The Oxen Be Deflated?'
Riddles II, v3
- T. Pratchett

-= Hawk =-, Nov 30, 2003

> Richard wrote:
>

>
>>> John Smith wrote:

>
>>>> I have no access to a proper protractor to do this with so I need to
>>>> know what the measurements are in cutting an angle. Assume we have at
>>>> our disposal a standard 2x4 and wish to cut a 60 degree angle.

>
>>> Got a graphics program? Some/most of the good ones will, when you draw
>>> a line, tell you its angle. Draw one that shows as 60 degrees. Print
>>> it. Transfer it to your stock.

>
>> Good idea. But what if you're out in the field and have only a hand saw, a
>> ruler, and a pencil?

>
> I'd be screwed.
>
>> Knowing that the height of the triangle is going to be 4 inches, what is the
>> length of the base of the triangle?

>
> For starters, a 2x4 isn't 2" x 4", so you're already in trouble if you're
> going to use a math approach, as you'll be starting from an incorrect
> dimension.

It is if it is planed.

>
>> If the base length is also 4 inches, we know that will give us a 45 degree
>> cut right?

>
> Yes, with base and alt the same -- not that those even-inch dimensions apply
> to a 2x4.
>
>> So to get 60 degrees, the base line length would be shorter yes?

>
> Or longer, depending on which vertex you wanted to be 60 degrees.
>
>> So what's the length needing to be?

>
> Dunno. Your limitations of what I have on hand don't include trig tables.
>
> I'll trade you that ruler for a compass. Don't need the ruler; could do this
> with the compass.

12. ### anthonyberetGuest

>
>> John Smith said:
>>
>>> I have no access to a proper protractor to do this with so I need
>>> to know what the measurements are in cutting an angle.
>>> Assume we have at our disposal a standard 2x4 and wish to cut a 60
>>> degree angle.
>>>
>>> What would the measurement be from the right side of the edge to
>>> the left most edge of the triangle?
>>> Assuming the top right edge is one corner, and the lower right edge
>>> is another corner.
>>>
>>> Or if you have a 60 degree fixed angle guide handy, measure each
>>> side and let me know what they are. Thanks.

>>
>> Draw a line between the 2 points, divide it into 10 equal lengths,
>> cut at the 6th division.

>
> Oops, before you get your saw out, redraw with 9 divisions, not 10.

I dont think that will work anyway......... what you are describing would
work along an arc but not where there is a straight edge involved.
--
You can't email me at the moment.
Do you use filesharing networks? If so, please visit my online poll:
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anthonyberet

anthonyberet, Nov 30, 2003
13. ### PatrickGuest

John Smith wrote:
> I have no access to a proper protractor to do this with so I need to
> know what the measurements are in cutting an angle.
> Assume we have at our disposal a standard 2x4 and wish to cut a 60
> degree angle.
>
> What would the measurement be from the right side of the edge to the
> left most edge of the triangle?
> Assuming the top right edge is one corner, and the lower right edge
> is another corner.
>
> Or if you have a 60 degree fixed angle guide handy, measure each side
> and let me know what they are. Thanks.

I've come up with a ratio of;
1 , 1.7320508075688772935274463415059

i.e. one side is to be ~1.7 times the other side

1|__
~1.7

Patrick, Nov 30, 2003
14. ### anthonyberetGuest

John Smith wrote:
> I have no access to a proper protractor to do this with so I need to
> know what the measurements are in cutting an angle.
> Assume we have at our disposal a standard 2x4 and wish to cut a 60
> degree angle.
>
> What would the measurement be from the right side of the edge to the
> left most edge of the triangle?
> Assuming the top right edge is one corner, and the lower right edge
> is another corner.
>
> Or if you have a 60 degree fixed angle guide handy, measure each side
> and let me know what they are. Thanks.

Use this right-angled triangle calculator:
http://www.ex.ac.uk/trol/scol/calrtri.htm

If I understand you correctly the top right corner will be 6.93 inches above
the lower left corner, measured along the length of the 2x4.
The line between them (the hypotenuse) will be 8 inches.

--
You can't email me at the moment.
Do you use filesharing networks? If so, please visit my online poll:
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anthonyberet

anthonyberet, Nov 30, 2003
15. ### ve3mdnGuest

This may be silly and not help. The easiest way to create a 60 degree angle
is to draw a triangle with all sides the same. As long as it is large enough
any side can be used as the base along the length of the board. If you want
a 30-60-90 triagle use even numbers for the previous triangle anmd measure
half way across on of the sides and draw a line to the opposite side.
Basically just fold the previous triangle in half. If you want the math the
side across from the 30 is 1 unit the side across from the 90 is 2 units and
the side across from the 60 is 1.7321units (square root of 3).

Eric
"John Smith" <> wrote in message
news:...
> I have no access to a proper protractor to do this with so I need to know

what
> the measurements are in cutting an angle.
> Assume we have at our disposal a standard 2x4 and wish to cut a 60 degree

angle.
>
> What would the measurement be from the right side of the edge to the left

most
> edge of the triangle?
> Assuming the top right edge is one corner, and the lower right edge is

another
> corner.
>
> Or if you have a 60 degree fixed angle guide handy, measure each side and

let me
> know what they are. Thanks.
>

ve3mdn, Nov 30, 2003
16. ### PatrickGuest

Patrick wrote:
> John Smith wrote:
>> I have no access to a proper protractor to do this with so I need to
>> know what the measurements are in cutting an angle.
>> Assume we have at our disposal a standard 2x4 and wish to cut a 60
>> degree angle.
>>
>> What would the measurement be from the right side of the edge to the
>> left most edge of the triangle?
>> Assuming the top right edge is one corner, and the lower right edge
>> is another corner.
>>
>> Or if you have a 60 degree fixed angle guide handy, measure each side
>> and let me know what they are. Thanks.

>
> I've come up with a ratio of;
> 1 , 1.7320508075688772935274463415059
>
> i.e. one side is to be ~1.7 times the other side
>
> 1|__
> ~1.7

Haveing seen 'anthonyberet' post, it appears that the hypotenuse is to be
twice the length of one of the other sides.
a
1|__b
~1.7 line ab=2

Patrick, Nov 30, 2003
17. ### anthonyberetGuest

Patrick wrote:
> Patrick wrote:
>> John Smith wrote:
>>> I have no access to a proper protractor to do this with so I need to
>>> know what the measurements are in cutting an angle.
>>> Assume we have at our disposal a standard 2x4 and wish to cut a 60
>>> degree angle.
>>>
>>> What would the measurement be from the right side of the edge to the
>>> left most edge of the triangle?
>>> Assuming the top right edge is one corner, and the lower right edge
>>> is another corner.
>>>
>>> Or if you have a 60 degree fixed angle guide handy, measure each
>>> side and let me know what they are. Thanks.

>>
>> I've come up with a ratio of;
>> 1 , 1.7320508075688772935274463415059
>>
>> i.e. one side is to be ~1.7 times the other side
>>
>> 1|__
>> ~1.7

>
> Haveing seen 'anthonyberet' post, it appears that the hypotenuse is
> to be twice the length of one of the other sides.
> a
> 1|__b
> ~1.7 line ab=2

I am not sure that I visualised the OP's problem properly, however the
calculator i linked to should solve his problem.
If Angle B is the one to be 60 degrees (I at first used angle A), then the
top corner would be 2.31 inches above the first and the hypotenuse 4.62
inches.
--
You can't email me at the moment.
Do you use filesharing networks? If so, please visit my online poll:
http://vote.sparklit.com/web_poll.spark/780772
anthonyberet

anthonyberet, Nov 30, 2003
18. ### bb3Guest

"Brian H¹©" <-vine.co.uk.invalid> wrote in message
news:rbkyb.2098\$...
>
> > Richard wrote:
> >

> >
> >>> John Smith wrote:

> >
> >>>> I have no access to a proper protractor to do this with so I need

to
> >>>> know what the measurements are in cutting an angle. Assume we

have at
> >>>> our disposal a standard 2x4 and wish to cut a 60 degree angle.

> >
> >>> Got a graphics program? Some/most of the good ones will, when you

draw
> >>> a line, tell you its angle. Draw one that shows as 60 degrees.

Print
> >>> it. Transfer it to your stock.

> >
> >> Good idea. But what if you're out in the field and have only a hand

saw, a
> >> ruler, and a pencil?

> >
> > I'd be screwed.
> >
> >> Knowing that the height of the triangle is going to be 4 inches,

what is the
> >> length of the base of the triangle?

> >
> > For starters, a 2x4 isn't 2" x 4", so you're already in trouble if

you're
> > going to use a math approach, as you'll be starting from an

incorrect
> > dimension.

>
> It is if it is planed.

Not in the US.
http://www.allexperts.com/previousqv.asp?QuestionID=3160186

<snip>

bb3, Nov 30, 2003

>> For starters, a 2x4 isn't 2" x 4", so you're already in trouble if you're
>> going to use a math approach, as you'll be starting from an incorrect
>> dimension.

>
> It is if it is planed.

2x4s are smaller than 2x4. How is planing going to make them larger?

--
Blinky - - - - - - - - - - - - - - - - - - - - - - - Linux RU 297263
[still no new sig]

Blinky the Shark, Nov 30, 2003

anthonyberet wrote:

>>> John Smith said:

>>>> I have no access to a proper protractor to do this with so I need
>>>> to know what the measurements are in cutting an angle.
>>>> Assume we have at our disposal a standard 2x4 and wish to cut a 60
>>>> degree angle.

>>>> What would the measurement be from the right side of the edge to
>>>> the left most edge of the triangle?
>>>> Assuming the top right edge is one corner, and the lower right edge
>>>> is another corner.

>>>> Or if you have a 60 degree fixed angle guide handy, measure each
>>>> side and let me know what they are. Thanks.

>>> Draw a line between the 2 points, divide it into 10 equal lengths,
>>> cut at the 6th division.

>> Oops, before you get your saw out, redraw with 9 divisions, not 10.

> I dont think that will work anyway......... what you are describing would
> work along an arc but not where there is a straight edge involved.

That's exactly correct.[1] That's why protractors are round.

[1]Even with the nine sections to which he correcected this original.

--
Blinky - - - - - - - - - - - - - - - - - - - - - - - Linux RU 297263
[still no new sig]

Blinky the Shark, Nov 30, 2003