Find an angle using Auto Cad

[kahaduwap]

How can I draw the figure in the attachment and find angle '0' using Auto Cad ?

[ReMark]

One option would be to get the angle of each line then do the math. The other option would be to use the Angular dimension feature, pick the two lines and watch what AutoCAD returns as the angle. Be sure to set your angle type and precision in the UNITS dialog window.

[SEANT]

Unless I'm misreading something, I don't think a trapezoid can have those dimensions.

 

Edit: Should the 30 mm be the perpendicular span between the 2650 and the 2100?

[Blackfish]

I'm affraid it's an impossible figure, because 2650 - 60 = 2590 > 2100

[kahaduwap]

I'm affraid it's an impossible figure, because 2650 - 60 = 2590 > 2100

 

 

I am sorry it is 2400 mm not 2650.

[kahaduwap]

Unless I'm misreading something, I don't think a trapezoid can have those dimensions.

 

Edit: Should the 30 mm be the perpendicular span between the 2650 and the 2100?

 

Sorry it is 2400 and 2100

[Blackfish]

Kahaduwap, it's still wrong! If that data is incorrect, it has to be more than 2590mm! Maybe it's 300mm at sides instead of 30mm?

[kahaduwap]

Kahaduwap, it's still wrong! If that data is incorrect, it has to be more than 2590mm! Maybe it's 300mm at sides instead of 30mm?

 

I am very sorry, it is 2140

[Blackfish]

Do you understand that it's not possible to draw figure like that using any program or even paper and pencil? Is it a joke?

2650-2x30=2590 which is greater than your 2140mm, so you are not able to join all ends togheter and to create a trapezoid!

[kahaduwap]

Do you understand that it's not possible to draw figure like that using any program or even paper and pencil? Is it a joke?

2650-2x30=2590 which is greater than your 2140mm, so you are not able to join all ends togheter and to create a trapezoid!

 

Dear Blackfish,

 

Sorry to trouble you again. Should it be 2130 ? Please refer attached diagram. If it is correct, pl. tell me how to draw a diagram like this and find angles using Auto Cad.

Thank You

[MSasu]

You should look on relative input; this succession of inputs will do the job (for the last sketch):

Command: LINE

Specify first point:

Specify next point or [undo]: @0,100

Specify next point or [undo]: @30

Specify next point or [Close/Undo]: @0,-130

Specify next point or [Close/Undo]: C

[Blackfish]

Sorry Kahaduwap, I misunderstood your last two emails

See the below drawing, it's just one end, but the second one loks the same

 

 

Any problem with drawing it just ask.

[MSasu]

@Blackfish: So you propose to build the parallel edge by offset (calculated) and get the end of sloped line by intersecting it with a circle? I’m afraid that this is an approximation which is an approach that should be avoided while you have tools to do the sketch at exact size!

[Blackfish]

@MSasu:

Not at all. It's pure geometry

You draw the bottom 2140mm long line, than circle R=30mm and then a vertical (perpendicular to the base) line started form C point offset 20mm (2140-2100=40 40/2=20mm) from the end (B). Where the line hits the circle we have point (A) from where the 2100mm long line starts. The dimension between horizontal lines is for information only.

[MSasu]

You are right, seems that I understood wrong your sketch! Sorry for my comment, then.

[Blackfish]

You are right, seems that I understood wrong your sketch! Sorry for my comment, then.

 

This strange thread is full of sorries and misunderstandings

[ReMark]

And here I thought all the OP wanted to know was how to determine the angle between two lines.

[cadvision]

 

so we can work out the angle Cos A = Adj/Hyp = 0.5 therefore A=60 degrees. B is then 120 degrees.

 

So basic drawing in CAD

 

draw a polyline

 

Command: _pline

Specify start point:

Current line-width is 0.000

Specify next point or [Arc/Halfwidth/Length/Undo/Width]: @2100

Specify next point or [Arc/Close/Halfwidth/Length/Undo/Width]: @30

Specify next point or [Arc/Close/Halfwidth/Length/Undo/Width]: @2130

Specify next point or [Arc/Close/Halfwidth/Length/Undo/Width]: c

 

Then use dimensions.

Edited May 25, 2012 by cadvision