# Can we have true 90 degrees when drawing sketches?
**URL:** https://discourse.shapr3d.com/t/can-we-have-true-90-degrees-when-drawing-sketches/19833
**Category:** Modeling Questions
**Created:** [June 12, 2022, 5:27pm UTC](https://discourse.shapr3d.com/t/can-we-have-true-90-degrees-when-drawing-sketches/19833 "2022-06-12T17:27:41Z")
**Posts on this page:** 9
**Page:** 1
### Author:  [@moto4p](https://discourse.shapr3d.com/u/moto4p)
#### Post date: [June 12, 2022, 5:27pm UTC](https://discourse.shapr3d.com/t/can-we-have-true-90-degrees-when-drawing-sketches/19833/1 "2022-06-12T17:27:41Z")
This is absurd !
[https://us1.discourse-cdn.com/flex002/uploads/shapr3d/original/2X/5/549bd67856fc76ed5a3cda1f35e3681459e59b58.mp4](https://us1.discourse-cdn.com/flex002/uploads/shapr3d/original/2X/5/549bd67856fc76ed5a3cda1f35e3681459e59b58.mp4)
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### Author:  [@TigerMike](https://discourse.shapr3d.com/u/TigerMike)
#### Post date: [June 12, 2022, 6:17pm UTC](https://discourse.shapr3d.com/t/can-we-have-true-90-degrees-when-drawing-sketches/19833/2 "2022-06-12T18:17:29Z")
I’m curious, do you have **Snap to Grid** turned off?
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### Author:  [@PEC](https://discourse.shapr3d.com/u/PEC)
#### Post date: [June 12, 2022, 10:34pm UTC](https://discourse.shapr3d.com/t/can-we-have-true-90-degrees-when-drawing-sketches/19833/3 "2022-06-12T22:34:26Z")
Hi,
Could you check there are not several vertical lines almost overlapping?
At t = 20 secondes, we clearly see a second line flashing, very close to the one you are applying the 90° constraint.
So, it is not clear which of the 2 lines is getting the 90° constraint with the first line of 2.15mm length.
Could you check also that the vertical line is really connected to the center of the circle? Because the 2.15mm displayed is the length of the highlighted line, but if the vertical line is not connected to it, it could explain what you experiment.
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### Author:  [@moto4p](https://discourse.shapr3d.com/u/moto4p)
#### Post date: [June 13, 2022, 3:00am UTC](https://discourse.shapr3d.com/t/can-we-have-true-90-degrees-when-drawing-sketches/19833/5 "2022-06-13T03:00:35Z")
> [@PEC](#):
>
> Hi,
>
> Could you check there are not several vertical lines almost overlapping?
> At t = 20 secondes, we clearly see a second line flashing, very close to the one you are applying the 90° constraint.
>
> 
>
> So, it is not clear which of the 2 lines is getting the 90° constraint with the first line of 2.15mm length.
> Could you check also that the vertical line is really connected to the center of the circle? Because the 2.15mm displayed is the length of the highlighted line, but if the vertical line is not connected to it, it could explain what you experiment.
>
> 
line 2 you have mentioned is beneath this sketch, they are not on the same plane.
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### Author:  [@moto4p](https://discourse.shapr3d.com/u/moto4p)
#### Post date: [June 13, 2022, 3:01am UTC](https://discourse.shapr3d.com/t/can-we-have-true-90-degrees-when-drawing-sketches/19833/6 "2022-06-13T03:01:15Z")
> [@TigerMike](#):
>
> I’m curious, do you have **Snap to Grid** turned off?
Snap to the Grid is on
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### Author:  [@moto4p](https://discourse.shapr3d.com/u/moto4p)
#### Post date: [June 13, 2022, 3:15am UTC](https://discourse.shapr3d.com/t/can-we-have-true-90-degrees-when-drawing-sketches/19833/7 "2022-06-13T03:15:02Z")
> [@PEC](#):
>
> Hi,
>
> Could you check there are not several vertical lines almost overlapping?
> At t = 20 secondes, we clearly see a second line flashing, very close to the one you are applying the 90° constraint.
>
> 
>
> So, it is not clear which of the 2 lines is getting the 90° constraint with the first line of 2.15mm length.
> Could you check also that the vertical line is really connected to the center of the circle? Because the 2.15mm displayed is the length of the highlighted line, but if the vertical line is not connected to it, it could explain what you experiment.
>
> 
Here’s another glitch with 90 degrees problem, you can see the red face and the green face are parallel, and the green face is 90 degrees to the yellow face, so the red face is supposed to be also 90 degrees to the yellow face, but the result is not.
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### Author:  [@PEC](https://discourse.shapr3d.com/u/PEC)
#### Post date: [June 13, 2022, 8:25am UTC](https://discourse.shapr3d.com/t/can-we-have-true-90-degrees-when-drawing-sketches/19833/8 "2022-06-13T08:25:28Z")
Hi
the “prl” indicator on the bottom of the screen allows for a small error in parallelism :
- 0.008° or less error is considered parallel, as shown in the first screen shoot.
- 0.009° or more error is considered a significant angle between the lines and displayed as such.
So you can’t rely on “prl” to be sure the faces or lines are mathematically parallel and states that the angle between them is exactly 180°. It is actually between 179,992° and 180,008°
I think the red and green faces are not exactly parallel but have a small angle of 0.007°, which is less than the tolerance used to trigger the “prl” indicator on the bottom of the screen.
---
### Author:  [@moto4p](https://discourse.shapr3d.com/u/moto4p)
#### Post date: [June 14, 2022, 6:49am UTC](https://discourse.shapr3d.com/t/can-we-have-true-90-degrees-when-drawing-sketches/19833/9 "2022-06-14T06:49:13Z")
> [@PEC](#):
>
> Hi
>
> the “prl” indicator on the bottom of the screen allows for a small error in parallelism :
>
> - 0.008° or less error is considered parallel, as shown in the first screen shoot.
> - 0.009° or more error is considered a significant angle between the lines and displayed as such.
>
> So you can’t rely on “prl” to be sure the faces or lines are mathematically parallel and states that the angle between them is exactly 180°. It is actually between 179,992° and 180,008°
>
> I think the red and green faces are not exactly parallel but have a small angle of 0.007°, which is less than the tolerance used to trigger the “prl” indicator on the bottom of the screen.
>
> 
>
> 
That is what I am trying to say, sometimes we do need a precise 90 degrees for some long shape part, even 0.009 degrees could make huge different between two sides.
---
### Author:  [@KPeter](https://discourse.shapr3d.com/u/KPeter)
#### Post date: [June 14, 2022, 11:08am UTC](https://discourse.shapr3d.com/t/can-we-have-true-90-degrees-when-drawing-sketches/19833/10 "2022-06-14T11:08:44Z")
Hi @moto4p, can you please share these Shapr3D designs in a support ticket? We’d be happy to check them
[https://support.shapr3d.com/hc/en-us/requests/new](https://support.shapr3d.com/hc/en-us/requests/new)