Is it mathematically possible to only have 3/4th cover?

In Is the DMG 3/4 cover diagram in 5e incorrect? the question asker points out the diagram shown in the DMG implies 3/4th cover, but it’s possible to get a better angle on the defender meaning they only have 1/2 cover.

Diagram showing various approaches to getting cover, from the DMG pages 250 and 251

Is it mathematically possible to construct a scenario where only 3/4th cover is possible? Intuitively I can’t think of a place to put the attacker in the diagram where one corner isn’t able to get 1/2 cover by picking a better square, whilst still having some attack on the defender.