Most accurate way to cut up a shape at 45 degrees

Question

I am working with the latest version of Adobe Illustrator. I have the following:

two rounded rectangles

I would like to cup the shape at the following location, so that I create a flat document icon that is folded in one corner:

slice line of rounded rectangle

How I can achieve this? The knife tool doesn't do straight lines! Even though I press Ctrl / Shift / Alt .. etc

Any help would be greatly appreciated.

Thank You.

I usually create a shape and use pathfinder panel to cut out some part. — Vnovak, Jun 26, 2014 at 10:45
Knowing what I'm trying to achieve, can you please walk me through what shape .. etc you'd create? And how you'd cut them using pathfinder panel? — J86, Jun 26, 2014 at 10:50
Take the pen/line tool and draw that line. Then in pathfinder use divide and delete the other part — joojaa, Jun 26, 2014 at 11:06

Vnovak · Accepted Answer · 2014-06-26 11:11:26Z

First of all, I worked in Outline mode (Ctrl+Y).

You have you shapes stacked.
Turn on Smart Guides (Ctrl+U) it will help to fit exactly into intersection points. Do a straight line of cut with Pen tool (P).
Do and complete any shape which will enclose your smaller rectangle
Select all shapes, open Pathfinder panel and use Trim.
Select unnecessary shapes with Direct Select (A), you can select even part of path or one point. And press Delete. At first press you will delete exactly what selected. After delete the whole path will be selected - press Delete second time.
Back to Normal mode (Ctrl+Y).

enter image description here

Komental · Accepted Answer · 2014-06-26 11:12:31Z

1

Click TRIM or MERGE in the pathfinder, then use the Direct selection tool and delete all unneeded anchor points! enter image description here

answered Jun 26, 2014 at 11:12

Komental

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1

Better not to keep opened paths.
– Vnovak
Jun 26, 2014 at 11:25
@Vnovak Better in what way?
– Komental
Jun 26, 2014 at 11:26
Opened path can be a cause of error (e.g. with some RIPs)
– Vnovak
Jun 26, 2014 at 11:28
@Vnovak OK. Mathematically the fill is calculated as if it is closed. I have never seen problems with that. You can easily close the path by Ctrl+J but I think it's just an extra unnecessary step in this case. :)
– Komental
Jun 26, 2014 at 11:32
Mathematically, stray points also must not raise errors :)
– Vnovak
Jun 26, 2014 at 11:35

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