[Proportional selection in Affinity Photo]

I would like to do a selection with a certain proportion. I know that doing a selection with SHIFT pressed I can do square selections.

The problem is that I want to do a selection with a proportion of 7 width and 4 height.

Anyone knows how to do that?

[Right panel dissapeared]

Thanks!!

[Digital versions of Woorkbooks]

Is there any possibility of buying a digital copy of Affinity Photo and Affinity Designer woorkbooks? 

The thing is that I preffer a digital version because shippments to Uruguay (were i live) are expensive and i preffer having the material in digital version because while I read I can practice, all in my computer.   

[Right panel dissapeared]

The right panels dissapeared on affinity designer and i dont know how to reestablish them. Please help