Delete corner

[Gnils89]

Hello,
I have drawn a rectangle in Affinity Designer and now I want to delete the top left corner (circled in red). How can I do that? Thank you very much.

 

 

[v_kyr]

Draw another triangle which in size covers just that area to delete (you have to rotate the triangle so it's hypothenuse can be placed glued to the shown triangle there), then select both layers (your rect and the new drawn triangle) and perform a geometric subtract operation (Layer -> Geometry -> Subtract).

[Old Bruce]

First convert to curves if not already done then add two nodes and delete the one in the corner.

[thomaso]

... or use the available corner option in the Context Toolbar: