[tapiwa]

This is really bad maths.

Imagine diagonal of X cm.

Imagine screen so tall and thin, that diagonal approaches vertical. Area is tiny.

As you swing same diagonal downwards, area increases. Till diagonal is 45% from horizontal.

As you keep going, area begins to reduce, until, when diagonal is almost horizontal, area is tiny.

Needing to get out more ...

[barrkel]

The assertion is true for all landscape orientation monitors, which has almost always been the case in this context. You're really clutching at straws with this pedantry (IMHO).