Making a trapezoidal shape out of a rectangular one?

[Krischu]

In the attached drawing I roughly draw what I would like to achieve. Making little trapzoids out of the rectangle, because otherwise, when folding, these "ears" will be conflicting and get in eachothers' way.

Bildschirmfoto 2019-07-04 um 18.11.40.png (50.26 KiB) Viewed 6332 times

[Husky]

Husky-2019.07.04-02.png (3.75 KiB) Viewed 6325 times

Depends on the drawing but this is done with ...
- the "Lengthen / Shorten tool for the horizontal lines,
- the "Tangent Point Circle" tool for the connection between horizontal line and radius,
- the "Break out Segment" tool to clean the transition between radius and line.

I recommend to do it once (lazy me!), copy it to the clipboard and use it for every needed situation.

[Krischu]

Thanks. Your solution, though looking nice, is not what I intended. The tangent to the half circle would be a perpendicular line. Think of these trapezoidal "ears" to be bent up by 90°. Then the tangent would result in an unwanted gap. It's a nuance, but important to me.

[Husky]

Regarding to your example and assuming you will bend it to 90 degree then it should be a triangle and not a trapezoid.